added unit test

Detail on https://github.com/rust-lang/regex/pull/613

.travis.yml

@@ -47,6 +47,7 @@ matrix:
 before_install:
   - set -e
   - rustup self update
+  - rustup component add rustfmt
 
 install:
   - sh ci/install.sh
@@ -60,6 +61,7 @@ before_script:
 
 script:
   - bash ci/script.sh
+  - cargo fmt --all -- --check
 
 before_deploy:
   - sh ci/before_deploy.sh

CHANGELOG.md

@@ -5,7 +5,15 @@ Tantivy 0.11.0
 - Various bugfixes in the query parser.
     - Better handling of hyphens in query parser. (#609)
     - Better handling of whitespaces.
+- Closes #498 - add support for Elastic-style unbounded range queries for alphanumeric types eg. "title:>hello", "weight:>=70.5", "height:<200" (@petr-tik)
+- API change around `Box<BoxableTokenizer>`. See detail in #629
+- Avoid rebuilding Regex automaton whenever a regex query is reused. #630 (@brainlock)
+ 
+## How to update?
 
+- `Box<dyn BoxableTokenizer>` has been replaced by a `BoxedTokenizer` struct.
+- Regex are now compiled when the `RegexQuery` instance is built. As a result, it can now return
+an error and handling the `Result` is required.
 
 Tantivy 0.10.1
 =====================

Cargo.toml

@@ -15,23 +15,23 @@ edition = "2018"
 [dependencies]
 base64 = "0.10.0"
 byteorder = "1.0"
-once_cell = "0.2"
-regex = "1.0"
+once_cell = "1.0"
+regex ={version = "1.3.0", default-features = false, features = ["std"]}
 tantivy-fst = "0.1"
 memmap = {version = "0.7", optional=true}
 lz4 = {version="1.20", optional=true}
 snap = {version="0.2"}
+derive_builder = "0.7"
 atomicwrites = {version="0.2.2", optional=true}
 tempfile = "3.0"
 log = "0.4"
-combine = ">=3.6.0,<4.0.0"
 serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 num_cpus = "1.2"
 fs2={version="0.4", optional=true}
 itertools = "0.8"
-levenshtein_automata = {version="0.1", features=["fst_automaton"]}
+levenshtein_automata = "0.1"
 notify = {version="4", optional=true}
 bit-set = "0.5"
 uuid = { version = "0.7.2", features = ["v4", "serde"] }
@@ -42,6 +42,7 @@ owning_ref = "0.4"
 stable_deref_trait = "1.0.0"
 rust-stemmers = "1.1"
 downcast-rs = { version="1.0" }
+tantivy-query-grammar = { path="./query-grammar" }
 bitpacking = {version="0.8", default-features = false, features=["bitpacker4x"]}
 census = "0.2"
 fnv = "1.0.6"
@@ -80,10 +81,14 @@ failpoints = ["fail/failpoints"]
 unstable = [] # useful for benches.
 wasm-bindgen = ["uuid/wasm-bindgen"]
 
+[workspace]
+members = ["query-grammar", "incremental-search"]
+
 [badges]
 travis-ci = { repository = "tantivy-search/tantivy" }
 
 [dev-dependencies.fail]
+version = "0.3"
 features = ["failpoints"]
 
 # Following the "fail" crate best practises, we isolate

Makefile

@@ -0,0 +1,3 @@
+test:
+	echo "Run test only... No examples."
+	cargo test --all --tests --lib

ci/script.sh

@@ -7,7 +7,7 @@ set -ex
 main() {
     if [ ! -z $CODECOV ]; then
         echo "Codecov"
-        cargo build --verbose && cargo coverage --verbose && bash <(curl -s https://codecov.io/bash) -s target/kcov
+        cargo build --verbose && cargo coverage --verbose --all && bash <(curl -s https://codecov.io/bash) -s target/kcov
     else
         echo "Build"
         cross build --target $TARGET
@@ -15,7 +15,8 @@ main() {
             return
         fi
         echo "Test"
-        cross test --target $TARGET --no-default-features --features mmap -- --test-threads 1
+        cross test --target $TARGET --no-default-features --features mmap
+        cross test --target $TARGET --no-default-features --features mmap query-grammar
     fi
     for example in $(ls examples/*.rs)
     do

examples/basic_search.rs

@@ -5,20 +5,17 @@
 //
 // We will :
 // - define our schema
-// = create an index in a directory
-// - index few documents in our index
-// - search for the best document matchings "sea whale"
-// - retrieve the best document original content.
+// - create an index in a directory
+// - index a few documents into our index
+// - search for the best document matching a basic query
+// - retrieve the best document's original content.
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
 use tantivy::schema::*;
-use tantivy::Index;
-use tantivy::ReloadPolicy;
+use tantivy::{doc, Index, ReloadPolicy};
 use tempfile::TempDir;
 
 fn main() -> tantivy::Result<()> {
@@ -33,7 +30,7 @@ fn main() -> tantivy::Result<()> {
     // and for each field, its type and "the way it should
     // be indexed".
 
-    // first we need to define a schema ...
+    // First we need to define a schema ...
     let mut schema_builder = Schema::builder();
 
     // Our first field is title.
@@ -48,7 +45,7 @@ fn main() -> tantivy::Result<()> {
     //
     // `STORED` means that the field will also be saved
     // in a compressed, row-oriented key-value store.
-    // This store is useful to reconstruct the
+    // This store is useful for reconstructing the
     // documents that were selected during the search phase.
     schema_builder.add_text_field("title", TEXT | STORED);
 
@@ -57,8 +54,7 @@ fn main() -> tantivy::Result<()> {
     // need to be able to be able to retrieve it
     // for our application.
     //
-    // We can make our index lighter and
-    // by omitting `STORED` flag.
+    // We can make our index lighter by omitting the `STORED` flag.
     schema_builder.add_text_field("body", TEXT);
 
     let schema = schema_builder.build();
@@ -71,7 +67,7 @@ fn main() -> tantivy::Result<()> {
     // with our schema in the directory.
     let index = Index::create_in_dir(&index_path, schema.clone())?;
 
-    // To insert document we need an index writer.
+    // To insert a document we will need an index writer.
     // There must be only one writer at a time.
     // This single `IndexWriter` is already
     // multithreaded.
@@ -149,8 +145,8 @@ fn main() -> tantivy::Result<()> {
     // At this point our documents are not searchable.
     //
     //
-    // We need to call .commit() explicitly to force the
-    // index_writer to finish processing the documents in the queue,
+    // We need to call `.commit()` explicitly to force the
+    // `index_writer` to finish processing the documents in the queue,
     // flush the current index to the disk, and advertise
     // the existence of new documents.
     //
@@ -162,14 +158,14 @@ fn main() -> tantivy::Result<()> {
     // persistently indexed.
     //
     // In the scenario of a crash or a power failure,
-    // tantivy behaves as if has rolled back to its last
+    // tantivy behaves as if it has rolled back to its last
     // commit.
 
     // # Searching
     //
     // ### Searcher
     //
-    // A reader is required to get search the index.
+    // A reader is required first in order to search an index.
     // It acts as a `Searcher` pool that reloads itself,
     // depending on a `ReloadPolicy`.
     //
@@ -185,7 +181,7 @@ fn main() -> tantivy::Result<()> {
 
     // We now need to acquire a searcher.
     //
-    // A searcher points to snapshotted, immutable version of the index.
+    // A searcher points to a snapshotted, immutable version of the index.
     //
     // Some search experience might require more than
     // one query. Using the same searcher ensures that all of these queries will run on the
@@ -205,7 +201,7 @@ fn main() -> tantivy::Result<()> {
     // in both title and body.
     let query_parser = QueryParser::for_index(&index, vec![title, body]);
 
-    // QueryParser may fail if the query is not in the right
+    // `QueryParser` may fail if the query is not in the right
     // format. For user facing applications, this can be a problem.
     // A ticket has been opened regarding this problem.
     let query = query_parser.parse_query("sea whale")?;
@@ -221,7 +217,7 @@ fn main() -> tantivy::Result<()> {
     //
     // We are not interested in all of the documents but
     // only in the top 10. Keeping track of our top 10 best documents
-    // is the role of the TopDocs.
+    // is the role of the `TopDocs` collector.
 
     // We can now perform our query.
     let top_docs = searcher.search(&query, &TopDocs::with_limit(10))?;

examples/custom_collector.rs

@@ -9,15 +9,12 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::{Collector, SegmentCollector};
 use tantivy::fastfield::FastFieldReader;
 use tantivy::query::QueryParser;
 use tantivy::schema::Field;
 use tantivy::schema::{Schema, FAST, INDEXED, TEXT};
-use tantivy::SegmentReader;
-use tantivy::{Index, TantivyError};
+use tantivy::{doc, Index, SegmentReader, TantivyError};
 
 #[derive(Default)]
 struct Stats {

examples/custom_tokenizer.rs

@@ -2,14 +2,11 @@
 //
 // In this example, we'll see how to define a tokenizer pipeline
 // by aligning a bunch of `TokenFilter`.
-
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
 use tantivy::schema::*;
 use tantivy::tokenizer::NgramTokenizer;
-use tantivy::Index;
+use tantivy::{doc, Index};
 
 fn main() -> tantivy::Result<()> {
     // # Defining the schema

examples/deleting_updating_documents.rs

@@ -8,13 +8,10 @@
 //
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::TopDocs;
 use tantivy::query::TermQuery;
 use tantivy::schema::*;
-use tantivy::Index;
-use tantivy::IndexReader;
+use tantivy::{doc, Index, IndexReader};
 
 // A simple helper function to fetch a single document
 // given its id from our index.

examples/faceted_search.rs

@@ -12,12 +12,10 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::FacetCollector;
 use tantivy::query::AllQuery;
 use tantivy::schema::*;
-use tantivy::Index;
+use tantivy::{doc, Index};
 use tempfile::TempDir;
 
 fn main() -> tantivy::Result<()> {

examples/integer_range_search.rs

@@ -2,14 +2,10 @@
 //
 // Below is an example of creating an indexed integer field in your schema
 // You can use RangeQuery to get a Count of all occurrences in a given range.
-
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::Count;
 use tantivy::query::RangeQuery;
 use tantivy::schema::{Schema, INDEXED};
-use tantivy::Index;
-use tantivy::Result;
+use tantivy::{doc, Index, Result};
 
 fn run() -> Result<()> {
     // For the sake of simplicity, this schema will only have 1 field

examples/iterating_docs_and_positions.rs

@@ -9,11 +9,8 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::schema::*;
-use tantivy::Index;
-use tantivy::{DocId, DocSet, Postings};
+use tantivy::{doc, DocId, DocSet, Index, Postings};
 
 fn main() -> tantivy::Result<()> {
     // We first create a schema for the sake of the

examples/multiple_producer.rs

@@ -25,14 +25,11 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use std::sync::{Arc, RwLock};
 use std::thread;
 use std::time::Duration;
 use tantivy::schema::{Schema, STORED, TEXT};
-use tantivy::Opstamp;
-use tantivy::{Index, IndexWriter};
+use tantivy::{doc, Index, IndexWriter, Opstamp};
 
 fn main() -> tantivy::Result<()> {
     // # Defining the schema
@@ -49,10 +46,9 @@ fn main() -> tantivy::Result<()> {
     thread::spawn(move || {
         // we index 100 times the document... for the sake of the example.
         for i in 0..100 {
-            let opstamp = {
-                // A read lock is sufficient here.
-                let index_writer_rlock = index_writer_clone_1.read().unwrap();
-                index_writer_rlock.add_document(
+            let opstamp = index_writer_clone_1
+                .read().unwrap() //< A read lock is sufficient here.
+                .add_document(
                     doc!(
                         title => "Of Mice and Men",
                         body => "A few miles south of Soledad, the Salinas River drops in close to the hillside \
@@ -63,8 +59,7 @@ fn main() -> tantivy::Result<()> {
                         fresh and green with every spring, carrying in their lower leaf junctures the \
                         debris of the winter’s flooding; and sycamores with mottled, white, recumbent \
                         limbs and branches that arch over the pool"
-                    ))
-            };
+                    ));
             println!("add doc {} from thread 1 - opstamp {}", i, opstamp);
             thread::sleep(Duration::from_millis(20));
         }

examples/snippet.rs

@@ -7,13 +7,10 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
 use tantivy::schema::*;
-use tantivy::Index;
-use tantivy::{Snippet, SnippetGenerator};
+use tantivy::{doc, Index, Snippet, SnippetGenerator};
 use tempfile::TempDir;
 
 fn main() -> tantivy::Result<()> {

examples/stop_words.rs

@@ -11,13 +11,11 @@
 
 // ---
 // Importing tantivy...
-#[macro_use]
-extern crate tantivy;
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
 use tantivy::schema::*;
 use tantivy::tokenizer::*;
-use tantivy::Index;
+use tantivy::{doc, Index};
 
 fn main() -> tantivy::Result<()> {
     // this example assumes you understand the content in `basic_search`

incremental-search/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "incremental-search"
+version = "0.11.0"
+authors = ["Paul Masurel <paul.masurel@gmail.com>"]
+edition = "2018"
+
+
+[dependencies]
+derive_builder = "0.7"
+tantivy = {path = ".."}

incremental-search/src/bitset.rs

@@ -0,0 +1,395 @@
+use std::fmt;
+use std::u64;
+
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub(crate) struct TinySet(u64);
+
+impl fmt::Debug for TinySet {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.into_iter().collect::<Vec<u32>>().fmt(f)
+    }
+}
+
+pub struct TinySetIterator(TinySet);
+impl Iterator for TinySetIterator {
+    type Item = u32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.pop_lowest()
+    }
+}
+
+impl IntoIterator for TinySet {
+    type Item = u32;
+    type IntoIter = TinySetIterator;
+    fn into_iter(self) -> Self::IntoIter {
+        TinySetIterator(self)
+    }
+}
+
+impl TinySet {
+    /// Returns an empty `TinySet`.
+    pub fn empty() -> TinySet {
+        TinySet(0u64)
+    }
+
+    /// Returns the complement of the set in `[0, 64[`.
+    fn complement(self) -> TinySet {
+        TinySet(!self.0)
+    }
+
+    /// Returns true iff the `TinySet` contains the element `el`.
+    pub fn contains(self, el: u32) -> bool {
+        !self.intersect(TinySet::singleton(el)).is_empty()
+    }
+
+    /// Returns the intersection of `self` and `other`
+    pub fn intersect(self, other: TinySet) -> TinySet {
+        TinySet(self.0 & other.0)
+    }
+
+    /// Creates a new `TinySet` containing only one element
+    /// within `[0; 64[`
+    #[inline(always)]
+    pub fn singleton(el: u32) -> TinySet {
+        TinySet(1u64 << u64::from(el))
+    }
+
+    /// Insert a new element within [0..64[
+    #[inline(always)]
+    pub fn insert(self, el: u32) -> TinySet {
+        self.union(TinySet::singleton(el))
+    }
+
+    /// Insert a new element within [0..64[
+    #[inline(always)]
+    pub fn insert_mut(&mut self, el: u32) -> bool {
+        let old = *self;
+        *self = old.insert(el);
+        old != *self
+    }
+
+    /// Returns the union of two tinysets
+    #[inline(always)]
+    pub fn union(self, other: TinySet) -> TinySet {
+        TinySet(self.0 | other.0)
+    }
+
+    /// Returns true iff the `TinySet` is empty.
+    #[inline(always)]
+    pub fn is_empty(self) -> bool {
+        self.0 == 0u64
+    }
+
+    /// Returns the lowest element in the `TinySet`
+    /// and removes it.
+    #[inline(always)]
+    pub fn pop_lowest(&mut self) -> Option<u32> {
+        if self.is_empty() {
+            None
+        } else {
+            let lowest = self.0.trailing_zeros() as u32;
+            self.0 ^= TinySet::singleton(lowest).0;
+            Some(lowest)
+        }
+    }
+
+    /// Returns a `TinySet` than contains all values up
+    /// to limit excluded.
+    ///
+    /// The limit is assumed to be strictly lower than 64.
+    pub fn range_lower(upper_bound: u32) -> TinySet {
+        TinySet((1u64 << u64::from(upper_bound % 64u32)) - 1u64)
+    }
+
+    /// Returns a `TinySet` that contains all values greater
+    /// or equal to the given limit, included. (and up to 63)
+    ///
+    /// The limit is assumed to be strictly lower than 64.
+    pub fn range_greater_or_equal(from_included: u32) -> TinySet {
+        TinySet::range_lower(from_included).complement()
+    }
+
+    pub fn clear(&mut self) {
+        self.0 = 0u64;
+    }
+
+    pub fn len(self) -> u32 {
+        self.0.count_ones()
+    }
+}
+
+#[derive(Clone)]
+pub struct BitSet {
+    tinysets: Box<[TinySet]>,
+    len: usize, //< Technically it should be u32, but we
+    // count multiple inserts.
+    // `usize` guards us from overflow.
+    max_value: u32,
+}
+
+fn num_buckets(max_val: u32) -> u32 {
+    (max_val + 63u32) / 64u32
+}
+
+impl BitSet {
+    /// Create a new `BitSet` that may contain elements
+    /// within `[0, max_val[`.
+    pub fn with_max_value(max_value: u32) -> BitSet {
+        let num_buckets = num_buckets(max_value);
+        let tinybisets = vec![TinySet::empty(); num_buckets as usize].into_boxed_slice();
+        BitSet {
+            tinysets: tinybisets,
+            len: 0,
+            max_value,
+        }
+    }
+
+    /// Removes all elements from the `BitSet`.
+    pub fn clear(&mut self) {
+        for tinyset in self.tinysets.iter_mut() {
+            *tinyset = TinySet::empty();
+        }
+    }
+
+    /// Returns the number of elements in the `BitSet`.
+    pub fn len(&self) -> usize {
+        self.len
+    }
+
+    /// Inserts an element in the `BitSet`
+    pub fn insert(&mut self, el: u32) {
+        // we do not check saturated els.
+        let higher = el / 64u32;
+        let lower = el % 64u32;
+        self.len += if self.tinysets[higher as usize].insert_mut(lower) {
+            1
+        } else {
+            0
+        };
+    }
+
+    /// Returns true iff the elements is in the `BitSet`.
+    pub fn contains(&self, el: u32) -> bool {
+        self.tinyset(el / 64u32).contains(el % 64)
+    }
+
+    /// Returns the first non-empty `TinySet` associated to a bucket lower
+    /// or greater than bucket.
+    ///
+    /// Reminder: the tiny set with the bucket `bucket`, represents the
+    /// elements from `bucket * 64` to `(bucket+1) * 64`.
+    pub(crate) fn first_non_empty_bucket(&self, bucket: u32) -> Option<u32> {
+        self.tinysets[bucket as usize..]
+            .iter()
+            .cloned()
+            .position(|tinyset| !tinyset.is_empty())
+            .map(|delta_bucket| bucket + delta_bucket as u32)
+    }
+
+    pub fn max_value(&self) -> u32 {
+        self.max_value
+    }
+
+    /// Returns the tiny bitset representing the
+    /// the set restricted to the number range from
+    /// `bucket * 64` to `(bucket + 1) * 64`.
+    pub(crate) fn tinyset(&self, bucket: u32) -> TinySet {
+        self.tinysets[bucket as usize]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::BitSet;
+    use super::TinySet;
+    use crate::docset::DocSet;
+    use crate::query::BitSetDocSet;
+    use crate::tests;
+    use crate::tests::generate_nonunique_unsorted;
+    use std::collections::BTreeSet;
+    use std::collections::HashSet;
+
+    #[test]
+    fn test_tiny_set() {
+        assert!(TinySet::empty().is_empty());
+        {
+            let mut u = TinySet::empty().insert(1u32);
+            assert_eq!(u.pop_lowest(), Some(1u32));
+            assert!(u.pop_lowest().is_none())
+        }
+        {
+            let mut u = TinySet::empty().insert(1u32).insert(1u32);
+            assert_eq!(u.pop_lowest(), Some(1u32));
+            assert!(u.pop_lowest().is_none())
+        }
+        {
+            let mut u = TinySet::empty().insert(2u32);
+            assert_eq!(u.pop_lowest(), Some(2u32));
+            u.insert_mut(1u32);
+            assert_eq!(u.pop_lowest(), Some(1u32));
+            assert!(u.pop_lowest().is_none());
+        }
+        {
+            let mut u = TinySet::empty().insert(63u32);
+            assert_eq!(u.pop_lowest(), Some(63u32));
+            assert!(u.pop_lowest().is_none());
+        }
+    }
+
+    #[test]
+    fn test_bitset() {
+        let test_against_hashset = |els: &[u32], max_value: u32| {
+            let mut hashset: HashSet<u32> = HashSet::new();
+            let mut bitset = BitSet::with_max_value(max_value);
+            for &el in els {
+                assert!(el < max_value);
+                hashset.insert(el);
+                bitset.insert(el);
+            }
+            for el in 0..max_value {
+                assert_eq!(hashset.contains(&el), bitset.contains(el));
+            }
+            assert_eq!(bitset.max_value(), max_value);
+        };
+
+        test_against_hashset(&[], 0);
+        test_against_hashset(&[], 1);
+        test_against_hashset(&[0u32], 1);
+        test_against_hashset(&[0u32], 100);
+        test_against_hashset(&[1u32, 2u32], 4);
+        test_against_hashset(&[99u32], 100);
+        test_against_hashset(&[63u32], 64);
+        test_against_hashset(&[62u32, 63u32], 64);
+    }
+
+    #[test]
+    fn test_bitset_large() {
+        let arr = generate_nonunique_unsorted(100_000, 5_000);
+        let mut btreeset: BTreeSet<u32> = BTreeSet::new();
+        let mut bitset = BitSet::with_max_value(100_000);
+        for el in arr {
+            btreeset.insert(el);
+            bitset.insert(el);
+        }
+        for i in 0..100_000 {
+            assert_eq!(btreeset.contains(&i), bitset.contains(i));
+        }
+        assert_eq!(btreeset.len(), bitset.len());
+        let mut bitset_docset = BitSetDocSet::from(bitset);
+        for el in btreeset.into_iter() {
+            bitset_docset.advance();
+            assert_eq!(bitset_docset.doc(), el);
+        }
+        assert!(!bitset_docset.advance());
+    }
+
+    #[test]
+    fn test_bitset_num_buckets() {
+        use super::num_buckets;
+        assert_eq!(num_buckets(0u32), 0);
+        assert_eq!(num_buckets(1u32), 1);
+        assert_eq!(num_buckets(64u32), 1);
+        assert_eq!(num_buckets(65u32), 2);
+        assert_eq!(num_buckets(128u32), 2);
+        assert_eq!(num_buckets(129u32), 3);
+    }
+
+    #[test]
+    fn test_tinyset_range() {
+        assert_eq!(
+            TinySet::range_lower(3).into_iter().collect::<Vec<u32>>(),
+            [0, 1, 2]
+        );
+        assert!(TinySet::range_lower(0).is_empty());
+        assert_eq!(
+            TinySet::range_lower(63).into_iter().collect::<Vec<u32>>(),
+            (0u32..63u32).collect::<Vec<_>>()
+        );
+        assert_eq!(
+            TinySet::range_lower(1).into_iter().collect::<Vec<u32>>(),
+            [0]
+        );
+        assert_eq!(
+            TinySet::range_lower(2).into_iter().collect::<Vec<u32>>(),
+            [0, 1]
+        );
+        assert_eq!(
+            TinySet::range_greater_or_equal(3)
+                .into_iter()
+                .collect::<Vec<u32>>(),
+            (3u32..64u32).collect::<Vec<_>>()
+        );
+    }
+
+    #[test]
+    fn test_bitset_len() {
+        let mut bitset = BitSet::with_max_value(1_000);
+        assert_eq!(bitset.len(), 0);
+        bitset.insert(3u32);
+        assert_eq!(bitset.len(), 1);
+        bitset.insert(103u32);
+        assert_eq!(bitset.len(), 2);
+        bitset.insert(3u32);
+        assert_eq!(bitset.len(), 2);
+        bitset.insert(103u32);
+        assert_eq!(bitset.len(), 2);
+        bitset.insert(104u32);
+        assert_eq!(bitset.len(), 3);
+    }
+
+    #[test]
+    fn test_bitset_clear() {
+        let mut bitset = BitSet::with_max_value(1_000);
+        let els = tests::sample(1_000, 0.01f64);
+        for &el in &els {
+            bitset.insert(el);
+        }
+        assert!(els.iter().all(|el| bitset.contains(*el)));
+        bitset.clear();
+        for el in 0u32..1000u32 {
+            assert!(!bitset.contains(el));
+        }
+    }
+}
+
+#[cfg(all(test, feature = "unstable"))]
+mod bench {
+
+    use super::BitSet;
+    use super::TinySet;
+    use test;
+
+    #[bench]
+    fn bench_tinyset_pop(b: &mut test::Bencher) {
+        b.iter(|| {
+            let mut tinyset = TinySet::singleton(test::black_box(31u32));
+            tinyset.pop_lowest();
+            tinyset.pop_lowest();
+            tinyset.pop_lowest();
+            tinyset.pop_lowest();
+            tinyset.pop_lowest();
+            tinyset.pop_lowest();
+        });
+    }
+
+    #[bench]
+    fn bench_tinyset_sum(b: &mut test::Bencher) {
+        let tiny_set = TinySet::empty().insert(10u32).insert(14u32).insert(21u32);
+        b.iter(|| {
+            assert_eq!(test::black_box(tiny_set).into_iter().sum::<u32>(), 45u32);
+        });
+    }
+
+    #[bench]
+    fn bench_tinyarr_sum(b: &mut test::Bencher) {
+        let v = [10u32, 14u32, 21u32];
+        b.iter(|| test::black_box(v).iter().cloned().sum::<u32>());
+    }
+
+    #[bench]
+    fn bench_bitset_initialize(b: &mut test::Bencher) {
+        b.iter(|| BitSet::with_max_value(1_000_000));
+    }
+}

incremental-search/src/lib.rs

@@ -0,0 +1,266 @@
+use tantivy::query::{BooleanQuery, FuzzyTermQuery, EmptyQuery};
+use derive_builder::Builder;
+use std::str::FromStr;
+use tantivy::query::{FuzzyConfiguration, FuzzyConfigurationBuilder, Query, Occur};
+use tantivy::schema::Field;
+use tantivy::{Searcher, TantivyError, DocAddress, Term, Document};
+use tantivy::collector::TopDocs;
+use std::ops::Deref;
+
+
+#[derive(Debug)]
+pub struct IncrementalSearchQuery {
+    pub terms: Vec<String>,
+    pub last_is_prefix: bool,
+}
+
+impl IncrementalSearchQuery {
+    pub fn fuzzy_configurations(&self) -> Vec<FuzzyConfigurations> {
+        if self.terms.is_empty() {
+            return Vec::default();
+        }
+        let single_term_confs: Vec<FuzzyConfigurationBuilder> = (0u8..3u8)
+            .map(|d: u8| {
+                let mut builder = FuzzyConfigurationBuilder::default();
+                builder.distance(d).transposition_cost_one(true);
+                builder
+            })
+            .collect();
+        let mut configurations: Vec<Vec<FuzzyConfigurationBuilder>> = single_term_confs
+            .iter()
+            .map(|conf| vec![conf.clone()])
+            .collect();
+        let mut new_configurations = Vec::new();
+        for _ in 1..self.terms.len() {
+            new_configurations.clear();
+            for single_term_conf in &single_term_confs {
+                for configuration in &configurations {
+                    let mut new_configuration: Vec<FuzzyConfigurationBuilder> = configuration.clone();
+                    new_configuration.push(single_term_conf.clone());
+                    new_configurations.push(new_configuration);
+                }
+            }
+            std::mem::swap(&mut configurations, &mut new_configurations);
+        }
+        if self.last_is_prefix {
+            for configuration in &mut configurations {
+                if let Some(last_conf) = configuration.last_mut() {
+                    last_conf.prefix(true);
+                }
+            }
+        }
+        let mut fuzzy_configurations: Vec<FuzzyConfigurations> = configurations
+            .into_iter()
+            .map(FuzzyConfigurations::from)
+            .collect();
+        fuzzy_configurations.sort_by(|left, right| left.cost.partial_cmp(&right.cost).unwrap());
+        fuzzy_configurations
+    }
+
+    fn search_query(&self, fields: &[Field], configurations: FuzzyConfigurations) -> Box<dyn Query> {
+        if self.terms.is_empty() {
+            Box::new(EmptyQuery)
+        } else if self.terms.len() == 1 {
+            build_query_for_fields(fields, &self.terms[0], &configurations.configurations[0])
+        } else {
+            Box::new(BooleanQuery::from(self.terms.iter()
+                .zip(configurations.configurations.iter())
+                .map(|(term, configuration)|
+                         (Occur::Must, build_query_for_fields(fields, &term, &configuration))
+                )
+                .collect::<Vec<_>>()))
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct FuzzyConfigurations {
+    configurations: Vec<FuzzyConfiguration>,
+    cost: f64,
+}
+
+
+fn compute_cost(fuzzy_confs: &[FuzzyConfiguration]) -> f64 {
+    fuzzy_confs
+        .iter()
+        .map(|fuzzy_conf| {
+            let weight = if fuzzy_conf.prefix { 30f64 } else { 5f64 };
+            weight * f64::from(fuzzy_conf.distance)
+        })
+        .sum()
+}
+
+impl From<Vec<FuzzyConfigurationBuilder>> for FuzzyConfigurations {
+    fn from(fuzzy_conf_builder: Vec<FuzzyConfigurationBuilder>) -> FuzzyConfigurations {
+        let configurations = fuzzy_conf_builder
+            .into_iter()
+            .map(|conf| conf.build().unwrap())
+            .collect::<Vec<FuzzyConfiguration>>();
+        let cost = compute_cost(&configurations);
+        FuzzyConfigurations {
+            configurations,
+            cost,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct ParseIncrementalQueryError;
+
+impl Into<TantivyError> for ParseIncrementalQueryError {
+    fn into(self) -> TantivyError {
+        TantivyError::InvalidArgument(format!("Invalid query: {:?}", self))
+    }
+}
+
+impl FromStr for IncrementalSearchQuery {
+    type Err = ParseIncrementalQueryError;
+
+    fn from_str(query_str: &str) -> Result<Self, Self::Err> {
+        let terms: Vec<String> = query_str
+            .split_whitespace()
+            .map(ToString::to_string)
+            .collect();
+        Ok(IncrementalSearchQuery {
+            terms,
+            last_is_prefix: query_str
+                .chars()
+                .last()
+                .map(|c| !c.is_whitespace())
+                .unwrap_or(false),
+        })
+    }
+}
+
+fn build_query_for_fields(fields: &[Field], term_text: &str, conf: &FuzzyConfiguration) -> Box<dyn Query> {
+    assert!(fields.len() > 0);
+    if fields.len() > 1 {
+        let term_queries: Vec<(Occur, Box<dyn Query>)> = fields
+            .iter()
+            .map(|&field| {
+                let term = Term::from_field_text(field, term_text);
+                let query = FuzzyTermQuery::new_from_configuration(term, conf.clone());
+                let boxed_query: Box<dyn Query> = Box::new(query);
+                (Occur::Must, boxed_query)
+            })
+            .collect();
+        Box::new(BooleanQuery::from(term_queries))
+    } else {
+        let term = Term::from_field_text(fields[0], term_text);
+        Box::new( FuzzyTermQuery::new_from_configuration(term, conf.clone()))
+    }
+
+}
+
+pub struct IncrementalSearchResult {
+    pub docs: Vec<Document>
+}
+
+#[derive(Builder, Default)]
+pub struct IncrementalSearch {
+    nhits: usize,
+    #[builder(default)]
+    search_fields: Vec<Field>,
+    #[builder(default)]
+    return_fields: Vec<Field>,
+}
+
+impl IncrementalSearch {
+
+    pub fn search<S: Deref<Target=Searcher>>(
+        &self,
+        query: &str,
+        searcher: &S,
+    ) -> tantivy::Result<IncrementalSearchResult> {
+        let searcher = searcher.deref();
+        let inc_search_query: IncrementalSearchQuery =
+            FromStr::from_str(query).map_err(Into::<TantivyError>::into)?;
+
+        let mut results: Vec<DocAddress> = Vec::default();
+        let mut remaining = self.nhits;
+        for fuzzy_conf in inc_search_query.fuzzy_configurations() {
+            if remaining == 0 {
+                break;
+            }
+            let query = inc_search_query.search_query(&self.search_fields[..], fuzzy_conf);
+            let new_docs = searcher.search(query.as_ref(), &TopDocs::with_limit(remaining))?;
+            // TODO(pmasurel) remove already added docs.
+            results.extend(new_docs.into_iter()
+                .map(|(_, doc_address)| doc_address));
+            remaining = self.nhits - results.len();
+            if remaining == 0 {
+                break;
+            }
+        }
+        let docs: Vec<Document> = results.into_iter()
+            .map(|doc_address: DocAddress| searcher.doc(doc_address))
+            .collect::<tantivy::Result<_>>()?;
+        Ok(IncrementalSearchResult {
+            docs
+        })
+    }
+}
+#[cfg(test)]
+mod tests {
+    use tantivy::doc;
+    use crate::{IncrementalSearch, IncrementalSearchBuilder, IncrementalSearchQuery};
+    use std::str::FromStr;
+    use tantivy::schema::{SchemaBuilder, TEXT, STORED};
+    use tantivy::Index;
+
+    #[test]
+    fn test_incremental_search() {
+        let incremental_search = IncrementalSearchBuilder::default()
+            .nhits(10)
+            .build()
+            .unwrap();
+    }
+
+    #[test]
+    fn test_incremental_search_query_parse_empty() {
+        let query = IncrementalSearchQuery::from_str("").unwrap();
+        assert_eq!(query.terms, Vec::<String>::new());
+        assert!(!query.last_is_prefix);
+    }
+
+    #[test]
+    fn test_incremental_search_query_parse_trailing_whitespace() {
+        let query = IncrementalSearchQuery::from_str("hello happy tax pa ").unwrap();
+        assert_eq!(query.terms, vec!["hello", "happy", "tax", "pa"]);
+        assert!(!query.last_is_prefix);
+    }
+
+    #[test]
+    fn test_incremental_search_query_parse_unicode_whitespace() {
+        let query = IncrementalSearchQuery::from_str("hello  happy tax pa ").unwrap();
+        assert_eq!(query.terms, vec!["hello", "happy", "tax", "pa"]);
+        assert!(!query.last_is_prefix);
+    }
+
+    #[test]
+    fn test_incremental_search_query_parse() {
+        let query = IncrementalSearchQuery::from_str("hello happy tax pa").unwrap();
+        assert_eq!(query.terms, vec!["hello", "happy", "tax", "pa"]);
+        assert!(query.last_is_prefix);
+    }
+
+    #[test]
+    fn test_blop() {
+        let mut schema_builder = SchemaBuilder::new();
+        let body = schema_builder.add_text_field("body", TEXT | STORED);
+        let schema = schema_builder.build();
+        let index = Index::create_in_ram(schema);
+        let mut index_writer = index.writer_with_num_threads(1, 30_000_000).unwrap();
+        index_writer.add_document(doc!(body=> "hello happy tax payer"));
+        index_writer.commit().unwrap();
+        let reader = index.reader().unwrap();
+        let searcher = reader.searcher();
+        let incremental_search: IncrementalSearch = IncrementalSearchBuilder::default()
+            .nhits(1)
+            .search_fields(vec![body])
+            .build()
+            .unwrap();
+        let top_docs = incremental_search.search("hello hapy t", &searcher).unwrap();
+        assert_eq!(top_docs.docs.len(), 1);
+    }
+}

query-grammar/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "tantivy-query-grammar"
+version = "0.11.0"
+authors = ["Paul Masurel <paul.masurel@gmail.com>"]
+license = "MIT"
+categories = ["database-implementations", "data-structures"]
+description = """Search engine library"""
+documentation = "https://tantivy-search.github.io/tantivy/tantivy/index.html"
+homepage = "https://github.com/tantivy-search/tantivy"
+repository = "https://github.com/tantivy-search/tantivy"
+readme = "README.md"
+keywords = ["search", "information", "retrieval"]
+edition = "2018"
+
+[dependencies]
+combine = ">=3.6.0,<4.0.0"

query-grammar/src/lib.rs

@@ -0,0 +1,17 @@
+#![recursion_limit = "100"]
+
+mod occur;
+mod query_grammar;
+mod user_input_ast;
+use combine::parser::Parser;
+
+pub use crate::occur::Occur;
+use crate::query_grammar::parse_to_ast;
+pub use crate::user_input_ast::{UserInputAST, UserInputBound, UserInputLeaf, UserInputLiteral};
+
+pub struct Error;
+
+pub fn parse_query(query: &str) -> Result<UserInputAST, Error> {
+    let (user_input_ast, _remaining) = parse_to_ast().parse(query).map_err(|_| Error)?;
+    Ok(user_input_ast)
+}

query-grammar/src/occur.rs

@@ -25,24 +25,24 @@ impl Occur {
             Occur::MustNot => '-',
         }
     }
-}
 
-/// Compose two occur values.
-pub fn compose_occur(left: Occur, right: Occur) -> Occur {
-    match left {
-        Occur::Should => right,
-        Occur::Must => {
-            if right == Occur::MustNot {
-                Occur::MustNot
-            } else {
-                Occur::Must
+    /// Compose two occur values.
+    pub fn compose(left: Occur, right: Occur) -> Occur {
+        match left {
+            Occur::Should => right,
+            Occur::Must => {
+                if right == Occur::MustNot {
+                    Occur::MustNot
+                } else {
+                    Occur::Must
+                }
             }
-        }
-        Occur::MustNot => {
-            if right == Occur::MustNot {
-                Occur::Must
-            } else {
-                Occur::MustNot
+            Occur::MustNot => {
+                if right == Occur::MustNot {
+                    Occur::Must
+                } else {
+                    Occur::MustNot
+                }
             }
         }
     }

query-grammar/src/query_grammar.rs

@@ -1,6 +1,5 @@
 use super::user_input_ast::*;
-use crate::query::occur::Occur;
-use crate::query::query_parser::user_input_ast::UserInputBound;
+use crate::Occur;
 use combine::char::*;
 use combine::error::StreamError;
 use combine::stream::StreamErrorFor;
@@ -83,28 +82,67 @@ parser! {
 }
 
 parser! {
+    /// Function that parses a range out of a Stream
+    /// Supports ranges like:
+    /// [5 TO 10], {5 TO 10}, [* TO 10], [10 TO *], {10 TO *], >5, <=10
+    /// [a TO *], [a TO c], [abc TO bcd}
     fn range[I]()(I) -> UserInputLeaf
     where [I: Stream<Item = char>] {
         let range_term_val = || {
             word().or(negative_number()).or(char('*').with(value("*".to_string())))
         };
+
+        // check for unbounded range in the form of <5, <=10, >5, >=5
+        let elastic_unbounded_range = (choice([attempt(string(">=")),
+                                               attempt(string("<=")),
+                                               attempt(string("<")),
+                                               attempt(string(">"))])
+                                       .skip(spaces()),
+                                       range_term_val()).
+            map(|(comparison_sign, bound): (&str, String)|
+                match comparison_sign {
+                    ">=" => (UserInputBound::Inclusive(bound), UserInputBound::Unbounded),
+                    "<=" => (UserInputBound::Unbounded, UserInputBound::Inclusive(bound)),
+                    "<" => (UserInputBound::Unbounded, UserInputBound::Exclusive(bound)),
+                    ">" => (UserInputBound::Exclusive(bound), UserInputBound::Unbounded),
+                    // default case
+                    _ => (UserInputBound::Unbounded, UserInputBound::Unbounded)
+                });
         let lower_bound = (one_of("{[".chars()), range_term_val())
             .map(|(boundary_char, lower_bound): (char, String)|
-                if boundary_char == '{' { UserInputBound::Exclusive(lower_bound) }
-                else { UserInputBound::Inclusive(lower_bound) });
+                 if lower_bound == "*" {
+                     UserInputBound::Unbounded
+                 } else if boundary_char == '{' {
+                         UserInputBound::Exclusive(lower_bound)
+                 } else {
+                     UserInputBound::Inclusive(lower_bound)
+                 });
         let upper_bound = (range_term_val(), one_of("}]".chars()))
             .map(|(higher_bound, boundary_char): (String, char)|
-                if boundary_char == '}' { UserInputBound::Exclusive(higher_bound) }
-                else { UserInputBound::Inclusive(higher_bound) });
-        (
-            optional(field()),
-            lower_bound
-            .skip((spaces(), string("TO"), spaces())),
-            upper_bound,
-        ).map(|(field, lower, upper)| UserInputLeaf::Range {
-                field,
-                lower,
-                upper
+                 if higher_bound == "*" {
+                     UserInputBound::Unbounded
+                 } else if boundary_char == '}' {
+                     UserInputBound::Exclusive(higher_bound)
+                 } else {
+                     UserInputBound::Inclusive(higher_bound)
+                 });
+         // return only lower and upper
+        let lower_to_upper = (lower_bound.
+                                    skip((spaces(),
+                                          string("TO"),
+                                          spaces())),
+                                    upper_bound);
+
+        (optional(field()).skip(spaces()),
+         // try elastic first, if it matches, the range is unbounded
+         attempt(elastic_unbounded_range).or(lower_to_upper))
+            .map(|(field, (lower, upper))|
+                 // Construct the leaf from extracted field (optional)
+                 // and bounds
+                 UserInputLeaf::Range {
+                     field,
+                     lower,
+                     upper
         })
     }
 }
@@ -258,6 +296,49 @@ mod test {
         );
     }
 
+    #[test]
+    fn test_parse_elastic_query_ranges() {
+        test_parse_query_to_ast_helper("title: >a", "title:{\"a\" TO \"*\"}");
+        test_parse_query_to_ast_helper("title:>=a", "title:[\"a\" TO \"*\"}");
+        test_parse_query_to_ast_helper("title: <a", "title:{\"*\" TO \"a\"}");
+        test_parse_query_to_ast_helper("title:<=a", "title:{\"*\" TO \"a\"]");
+        test_parse_query_to_ast_helper("title:<=bsd", "title:{\"*\" TO \"bsd\"]");
+
+        test_parse_query_to_ast_helper("weight: >70", "weight:{\"70\" TO \"*\"}");
+        test_parse_query_to_ast_helper("weight:>=70", "weight:[\"70\" TO \"*\"}");
+        test_parse_query_to_ast_helper("weight: <70", "weight:{\"*\" TO \"70\"}");
+        test_parse_query_to_ast_helper("weight:<=70", "weight:{\"*\" TO \"70\"]");
+        test_parse_query_to_ast_helper("weight: >60.7", "weight:{\"60.7\" TO \"*\"}");
+
+        test_parse_query_to_ast_helper("weight: <= 70", "weight:{\"*\" TO \"70\"]");
+
+        test_parse_query_to_ast_helper("weight: <= 70.5", "weight:{\"*\" TO \"70.5\"]");
+    }
+
+    #[test]
+    fn test_range_parser() {
+        // testing the range() parser separately
+        let res = range().parse("title: <hello").unwrap().0;
+        let expected = UserInputLeaf::Range {
+            field: Some("title".to_string()),
+            lower: UserInputBound::Unbounded,
+            upper: UserInputBound::Exclusive("hello".to_string()),
+        };
+        let res2 = range().parse("title:{* TO hello}").unwrap().0;
+        assert_eq!(res, expected);
+        assert_eq!(res2, expected);
+        let expected_weight = UserInputLeaf::Range {
+            field: Some("weight".to_string()),
+            lower: UserInputBound::Inclusive("71.2".to_string()),
+            upper: UserInputBound::Unbounded,
+        };
+
+        let res3 = range().parse("weight: >=71.2").unwrap().0;
+        let res4 = range().parse("weight:[71.2 TO *}").unwrap().0;
+        assert_eq!(res3, expected_weight);
+        assert_eq!(res4, expected_weight);
+    }
+
     #[test]
     fn test_parse_query_to_triming_spaces() {
         test_parse_query_to_ast_helper("   abc", "\"abc\"");
@@ -291,7 +372,7 @@ mod test {
         test_parse_query_to_ast_helper("[1 TO 5]", "[\"1\" TO \"5\"]");
         test_parse_query_to_ast_helper("foo:{a TO z}", "foo:{\"a\" TO \"z\"}");
         test_parse_query_to_ast_helper("foo:[1 TO toto}", "foo:[\"1\" TO \"toto\"}");
-        test_parse_query_to_ast_helper("foo:[* TO toto}", "foo:[\"*\" TO \"toto\"}");
+        test_parse_query_to_ast_helper("foo:[* TO toto}", "foo:{\"*\" TO \"toto\"}");
         test_parse_query_to_ast_helper("foo:[1 TO *}", "foo:[\"1\" TO \"*\"}");
         test_parse_query_to_ast_helper("foo:[1.1 TO *}", "foo:[\"1.1\" TO \"*\"}");
         test_is_parse_err("abc +    ");

query-grammar/src/user_input_ast.rs

@@ -1,8 +1,9 @@
 use std::fmt;
 use std::fmt::{Debug, Formatter};
 
-use crate::query::Occur;
+use crate::Occur;
 
+#[derive(PartialEq)]
 pub enum UserInputLeaf {
     Literal(UserInputLiteral),
     All,
@@ -35,6 +36,7 @@ impl Debug for UserInputLeaf {
     }
 }
 
+#[derive(PartialEq)]
 pub struct UserInputLiteral {
     pub field_name: Option<String>,
     pub phrase: String,
@@ -49,9 +51,11 @@ impl fmt::Debug for UserInputLiteral {
     }
 }
 
+#[derive(PartialEq)]
 pub enum UserInputBound {
     Inclusive(String),
     Exclusive(String),
+    Unbounded,
 }
 
 impl UserInputBound {
@@ -59,6 +63,7 @@ impl UserInputBound {
         match *self {
             UserInputBound::Inclusive(ref word) => write!(formatter, "[\"{}\"", word),
             UserInputBound::Exclusive(ref word) => write!(formatter, "{{\"{}\"", word),
+            UserInputBound::Unbounded => write!(formatter, "{{\"*\""),
         }
     }
 
@@ -66,6 +71,7 @@ impl UserInputBound {
         match *self {
             UserInputBound::Inclusive(ref word) => write!(formatter, "\"{}\"]", word),
             UserInputBound::Exclusive(ref word) => write!(formatter, "\"{}\"}}", word),
+            UserInputBound::Unbounded => write!(formatter, "\"*\"}}"),
         }
     }
 
@@ -73,6 +79,7 @@ impl UserInputBound {
         match *self {
             UserInputBound::Inclusive(ref contents) => contents,
             UserInputBound::Exclusive(ref contents) => contents,
+            UserInputBound::Unbounded => &"*",
         }
     }
 }

src/collector/count_collector.rs

@@ -10,12 +10,10 @@ use crate::SegmentReader;
 /// documents match the query.
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Schema, TEXT};
-/// use tantivy::{Index, Result};
 /// use tantivy::collector::Count;
 /// use tantivy::query::QueryParser;
+/// use tantivy::schema::{Schema, TEXT};
+/// use tantivy::{doc, Index, Result};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {

src/collector/facet_collector.rs

@@ -81,12 +81,10 @@ fn facet_depth(facet_bytes: &[u8]) -> usize {
 ///
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Facet, Schema, TEXT};
-/// use tantivy::{Index, Result};
 /// use tantivy::collector::FacetCollector;
 /// use tantivy::query::AllQuery;
+/// use tantivy::schema::{Facet, Schema, TEXT};
+/// use tantivy::{doc, Index, Result};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {

src/collector/mod.rs

@@ -35,7 +35,6 @@ The resulting `Fruit` will then be a typed tuple with each collector's original
 in their respective position.
 
 ```rust
-# extern crate tantivy;
 # use tantivy::schema::*;
 # use tantivy::*;
 # use tantivy::query::*;

src/collector/multi_collector.rs

@@ -105,12 +105,10 @@ impl<TFruit: Fruit> FruitHandle<TFruit> {
 /// [Combining several collectors section of the collector documentation](./index.html#combining-several-collectors).
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Schema, TEXT};
-/// use tantivy::{Index, Result};
 /// use tantivy::collector::{Count, TopDocs, MultiCollector};
 /// use tantivy::query::QueryParser;
+/// use tantivy::schema::{Schema, TEXT};
+/// use tantivy::{doc, Index, Result};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {

src/collector/top_score_collector.rs

@@ -23,13 +23,10 @@ use std::fmt;
 /// is `O(n log K)`.
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::DocAddress;
-/// use tantivy::schema::{Schema, TEXT};
-/// use tantivy::{Index, Result};
 /// use tantivy::collector::TopDocs;
 /// use tantivy::query::QueryParser;
+/// use tantivy::schema::{Schema, TEXT};
+/// use tantivy::{doc, DocAddress, Index, Result};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {
@@ -87,10 +84,8 @@ impl TopDocs {
     /// Set top-K to rank documents by a given fast field.
     ///
     /// ```rust
-    /// #[macro_use]
-    /// extern crate tantivy;
     /// # use tantivy::schema::{Schema, FAST, TEXT};
-    /// # use tantivy::{Index, Result, DocAddress};
+    /// # use tantivy::{doc, Index, Result, DocAddress};
     /// # use tantivy::query::{Query, QueryParser};
     /// use tantivy::Searcher;
     /// use tantivy::collector::TopDocs;
@@ -128,7 +123,7 @@ impl TopDocs {
     /// ///
     /// /// `field` is required to be a FAST field.
     /// fn docs_sorted_by_rating(searcher: &Searcher,
-    ///                          query: &Query,
+    ///                          query: &dyn Query,
     ///                          sort_by_field: Field)
     ///     -> Result<Vec<(u64, DocAddress)>> {
     ///
@@ -197,10 +192,8 @@ impl TopDocs {
     /// learning-to-rank model over various features
     ///
     /// ```rust
-    /// #[macro_use]
-    /// extern crate tantivy;
     /// # use tantivy::schema::{Schema, FAST, TEXT};
-    /// # use tantivy::{Index, DocAddress, DocId, Score};
+    /// # use tantivy::{doc, Index, DocAddress, DocId, Score};
     /// # use tantivy::query::QueryParser;
     /// use tantivy::SegmentReader;
     /// use tantivy::collector::TopDocs;
@@ -302,10 +295,8 @@ impl TopDocs {
     /// # Example
     ///
     /// ```rust
-    /// # #[macro_use]
-    /// # extern crate tantivy;
     /// # use tantivy::schema::{Schema, FAST, TEXT};
-    /// # use tantivy::{Index, DocAddress, DocId};
+    /// # use tantivy::{doc, Index, DocAddress, DocId};
     /// # use tantivy::query::QueryParser;
     /// use tantivy::SegmentReader;
     /// use tantivy::collector::TopDocs;

src/core/index.rs

@@ -173,11 +173,11 @@ impl Index {
     }
 
     /// Helper to access the tokenizer associated to a specific field.
-    pub fn tokenizer_for_field(&self, field: Field) -> Result<Box<dyn BoxedTokenizer>> {
+    pub fn tokenizer_for_field(&self, field: Field) -> Result<BoxedTokenizer> {
         let field_entry = self.schema.get_field_entry(field);
         let field_type = field_entry.field_type();
         let tokenizer_manager: &TokenizerManager = self.tokenizers();
-        let tokenizer_name_opt: Option<Box<dyn BoxedTokenizer>> = match field_type {
+        let tokenizer_name_opt: Option<BoxedTokenizer> = match field_type {
             FieldType::Str(text_options) => text_options
                 .get_indexing_options()
                 .map(|text_indexing_options| text_indexing_options.tokenizer().to_string())
@@ -216,8 +216,22 @@ impl Index {
         Index::open(mmap_directory)
     }
 
-    pub(crate) fn inventory(&self) -> &SegmentMetaInventory {
-        &self.inventory
+    /// Returns the list of the segment metas tracked by the index.
+    ///
+    /// Such segments can of course be part of the index,
+    /// but also they could be segments being currently built or in the middle of a merge
+    /// operation.
+    pub fn list_all_segment_metas(&self) -> Vec<SegmentMeta> {
+        self.inventory.all()
+    }
+
+    /// Creates a new segment_meta (Advanced user only).
+    ///
+    /// As long as the `SegmentMeta` lives, the files associated with the
+    /// `SegmentMeta` are guaranteed to not be garbage collected, regardless of
+    /// whether the segment is recorded as part of the index or not.
+    pub fn new_segment_meta(&self, segment_id: SegmentId, max_doc: u32) -> SegmentMeta {
+        self.inventory.new_segment_meta(segment_id, max_doc)
     }
 
     /// Open the index using the provided directory

src/core/index_meta.rs

@@ -30,7 +30,6 @@ impl SegmentMetaInventory {
             .collect::<Vec<_>>()
     }
 
-    #[doc(hidden)]
     pub fn new_segment_meta(&self, segment_id: SegmentId, max_doc: u32) -> SegmentMeta {
         let inner = InnerSegmentMeta {
             segment_id,

src/core/segment_id.rs

@@ -4,6 +4,8 @@ use uuid::Uuid;
 
 #[cfg(test)]
 use once_cell::sync::Lazy;
+use std::error::Error;
+use std::str::FromStr;
 #[cfg(test)]
 use std::sync::atomic;
 
@@ -52,15 +54,51 @@ impl SegmentId {
     /// and the rest is random.
     ///
     /// Picking the first 8 chars is ok to identify
-    /// segments in a display message.
+    /// segments in a display message (e.g. a5c4dfcb).
     pub fn short_uuid_string(&self) -> String {
         (&self.0.to_simple_ref().to_string()[..8]).to_string()
     }
 
     /// Returns a segment uuid string.
+    ///
+    /// It consists in 32 lowercase hexadecimal chars
+    /// (e.g. a5c4dfcbdfe645089129e308e26d5523)
     pub fn uuid_string(&self) -> String {
         self.0.to_simple_ref().to_string()
     }
+
+    /// Build a `SegmentId` string from the full uuid string.
+    ///
+    /// E.g. "a5c4dfcbdfe645089129e308e26d5523"
+    pub fn from_uuid_string(uuid_string: &str) -> Result<SegmentId, SegmentIdParseError> {
+        FromStr::from_str(uuid_string)
+    }
+}
+
+/// Error type used when parsing a `SegmentId` from a string fails.
+pub struct SegmentIdParseError(uuid::parser::ParseError);
+
+impl Error for SegmentIdParseError {}
+
+impl fmt::Debug for SegmentIdParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl fmt::Display for SegmentIdParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl FromStr for SegmentId {
+    type Err = SegmentIdParseError;
+
+    fn from_str(uuid_string: &str) -> Result<Self, SegmentIdParseError> {
+        let uuid = Uuid::parse_str(uuid_string).map_err(SegmentIdParseError)?;
+        Ok(SegmentId(uuid))
+    }
 }
 
 impl fmt::Debug for SegmentId {
@@ -80,3 +118,18 @@ impl Ord for SegmentId {
         self.0.as_bytes().cmp(other.0.as_bytes())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::SegmentId;
+
+    #[test]
+    fn test_to_uuid_string() {
+        let full_uuid = "a5c4dfcbdfe645089129e308e26d5523";
+        let segment_id = SegmentId::from_uuid_string(full_uuid).unwrap();
+        assert_eq!(segment_id.uuid_string(), full_uuid);
+        assert_eq!(segment_id.short_uuid_string(), "a5c4dfcb");
+        // one extra char
+        assert!(SegmentId::from_uuid_string("a5c4dfcbdfe645089129e308e26d5523b").is_err());
+    }
+}

src/indexer/index_writer.rs

@@ -209,10 +209,7 @@ fn index_documents(
     assert!(num_docs > 0);
 
     let doc_opstamps: Vec<Opstamp> = segment_writer.finalize()?;
-    let segment_meta = segment
-        .index()
-        .inventory()
-        .new_segment_meta(segment_id, num_docs);
+    let segment_meta = segment.index().new_segment_meta(segment_id, num_docs);
 
     let last_docstamp: Opstamp = *(doc_opstamps.last().unwrap());
 
@@ -450,12 +447,10 @@ impl IndexWriter {
     /// by clearing and resubmitting necessary documents
     ///
     /// ```rust
-    /// #[macro_use]
-    /// extern crate tantivy;
-    /// use tantivy::query::QueryParser;
     /// use tantivy::collector::TopDocs;
+    /// use tantivy::query::QueryParser;
     /// use tantivy::schema::*;
-    /// use tantivy::Index;
+    /// use tantivy::{doc, Index};
     ///
     /// fn main() -> tantivy::Result<()> {
     ///     let mut schema_builder = Schema::builder();

src/indexer/segment_updater.rs

@@ -126,9 +126,7 @@ fn perform_merge(
 
     let num_docs = merger.write(segment_serializer)?;
 
-    let segment_meta = index
-        .inventory()
-        .new_segment_meta(merged_segment.id(), num_docs);
+    let segment_meta = index.new_segment_meta(merged_segment.id(), num_docs);
 
     let after_merge_segment_entry = SegmentEntry::new(segment_meta.clone(), delete_cursor, None);
     Ok(after_merge_segment_entry)
@@ -282,7 +280,7 @@ impl SegmentUpdater {
     fn list_files(&self) -> HashSet<PathBuf> {
         let mut files = HashSet::new();
         files.insert(META_FILEPATH.to_path_buf());
-        for segment_meta in self.0.index.inventory().all() {
+        for segment_meta in self.0.index.list_all_segment_metas() {
             files.extend(segment_meta.list_files());
         }
         files

src/indexer/segment_writer.rs

@@ -49,7 +49,7 @@ pub struct SegmentWriter {
     fast_field_writers: FastFieldsWriter,
     fieldnorms_writer: FieldNormsWriter,
     doc_opstamps: Vec<Opstamp>,
-    tokenizers: Vec<Option<Box<dyn BoxedTokenizer>>>,
+    tokenizers: Vec<Option<BoxedTokenizer>>,
 }
 
 impl SegmentWriter {

src/lib.rs

@@ -1,5 +1,4 @@
 #![doc(html_logo_url = "http://fulmicoton.com/tantivy-logo/tantivy-logo.png")]
-#![recursion_limit = "100"]
 #![cfg_attr(all(feature = "unstable", test), feature(test))]
 #![cfg_attr(feature = "cargo-clippy", allow(clippy::module_inception))]
 #![doc(test(attr(allow(unused_variables), deny(warnings))))]
@@ -11,21 +10,12 @@
 //! Think `Lucene`, but in Rust.
 //!
 //! ```rust
-
-//! # extern crate tempfile;
-//! #
-//! #[macro_use]
-//! extern crate tantivy;
-//!
-//! // ...
-//!
 //! # use std::path::Path;
 //! # use tempfile::TempDir;
-//! # use tantivy::Index;
-//! # use tantivy::schema::*;
-//! # use tantivy::{Score, DocAddress};
 //! # use tantivy::collector::TopDocs;
 //! # use tantivy::query::QueryParser;
+//! # use tantivy::schema::*;
+//! # use tantivy::{doc, DocAddress, Index, Score};
 //! #
 //! # fn main() {
 //! #     // Let's create a temporary directory for the

src/macros.rs

@@ -22,11 +22,9 @@
 ///
 /// # Example
 ///
-/// ```
-/// #[macro_use]
-/// extern crate tantivy;
-///
+/// ```rust
 /// use tantivy::schema::{Schema, TEXT, FAST};
+/// use tantivy::doc;
 ///
 /// //...
 ///

src/query/automaton_weight.rs

@@ -8,15 +8,13 @@ use crate::termdict::{TermDictionary, TermStreamer};
 use crate::DocId;
 use crate::TantivyError;
 use crate::{Result, SkipResult};
+use std::sync::Arc;
 use tantivy_fst::Automaton;
 
 /// A weight struct for Fuzzy Term and Regex Queries
-pub struct AutomatonWeight<A>
-where
-    A: Automaton + Send + Sync + 'static,
-{
+pub struct AutomatonWeight<A> {
     field: Field,
-    automaton: A,
+    automaton: Arc<A>,
 }
 
 impl<A> AutomatonWeight<A>
@@ -24,12 +22,16 @@ where
     A: Automaton + Send + Sync + 'static,
 {
     /// Create a new AutomationWeight
-    pub fn new(field: Field, automaton: A) -> AutomatonWeight<A> {
-        AutomatonWeight { field, automaton }
+    pub fn new<IntoArcA: Into<Arc<A>>>(field: Field, automaton: IntoArcA) -> AutomatonWeight<A> {
+        AutomatonWeight {
+            field,
+            automaton: automaton.into(),
+        }
     }
 
     fn automaton_stream<'a>(&'a self, term_dict: &'a TermDictionary) -> TermStreamer<'a, &'a A> {
-        let term_stream_builder = term_dict.search(&self.automaton);
+        let automaton: &A = &*self.automaton;
+        let term_stream_builder = term_dict.search(automaton);
         term_stream_builder.into_stream()
     }
 }

src/query/fuzzy_query.rs

@@ -1,12 +1,14 @@
 use crate::error::TantivyError::InvalidArgument;
 use crate::query::{AutomatonWeight, Query, Weight};
 use crate::schema::Term;
+use crate::termdict::WrappedDFA;
 use crate::Result;
 use crate::Searcher;
-use levenshtein_automata::{LevenshteinAutomatonBuilder, DFA};
+use levenshtein_automata::{Distance, LevenshteinAutomatonBuilder, DFA};
 use once_cell::sync::Lazy;
 use std::collections::HashMap;
 use std::ops::Range;
+use derive_builder::Builder;
 
 /// A range of Levenshtein distances that we will build DFAs for our terms
 /// The computation is exponential, so best keep it to low single digits
@@ -24,16 +26,46 @@ static LEV_BUILDER: Lazy<HashMap<(u8, bool), LevenshteinAutomatonBuilder>> = Laz
     lev_builder_cache
 });
 
+
+#[derive(Builder, Default, Clone, Debug)]
+pub struct FuzzyConfiguration {
+    /// How many changes are we going to allow
+    pub distance: u8,
+    /// Should a transposition cost 1 or 2?
+    #[builder(default)]
+    pub transposition_cost_one: bool,
+    #[builder(default)]
+    pub prefix: bool,
+    /// If true, only the term with a levenshtein of exactly `distance` will match.
+    /// If false, terms at a distance `<=` to `distance` will match.
+    #[builder(default)]
+    pub exact_distance: bool,
+}
+
+fn build_dfa(fuzzy_configuration: &FuzzyConfiguration, term_text: &str) -> Result<DFA> {
+    let automaton_builder = LEV_BUILDER
+        .get(&(fuzzy_configuration.distance, fuzzy_configuration.transposition_cost_one))
+        .ok_or_else(|| {
+            InvalidArgument(format!(
+                "Levenshtein distance of {} is not allowed. Choose a value in the {:?} range",
+                fuzzy_configuration.distance, VALID_LEVENSHTEIN_DISTANCE_RANGE
+            ))
+        })?;
+    if fuzzy_configuration.prefix {
+        Ok(automaton_builder.build_prefix_dfa(term_text))
+    } else {
+        Ok(automaton_builder.build_dfa(term_text))
+    }
+}
+
 /// A Fuzzy Query matches all of the documents
 /// containing a specific term that is within
 /// Levenshtein distance
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Schema, TEXT};
-/// use tantivy::{Index, Result, Term};
 /// use tantivy::collector::{Count, TopDocs};
 /// use tantivy::query::FuzzyTermQuery;
+/// use tantivy::schema::{Schema, TEXT};
+/// use tantivy::{doc, Index, Result, Term};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {
@@ -43,32 +75,19 @@ static LEV_BUILDER: Lazy<HashMap<(u8, bool), LevenshteinAutomatonBuilder>> = Laz
 ///     let index = Index::create_in_ram(schema);
 ///     {
 ///         let mut index_writer = index.writer(3_000_000)?;
-///         index_writer.add_document(doc!(
-///             title => "The Name of the Wind",
-///         ));
-///         index_writer.add_document(doc!(
-///             title => "The Diary of Muadib",
-///         ));
-///         index_writer.add_document(doc!(
-///             title => "A Dairy Cow",
-///         ));
-///         index_writer.add_document(doc!(
-///             title => "The Diary of a Young Girl",
-///         ));
+///         index_writer.add_document(doc!(title => "The Name of the Wind"));
+///         index_writer.add_document(doc!(title => "The Diary of Muadib"));
+///         index_writer.add_document(doc!(title => "A Dairy Cow"));
+///         index_writer.add_document(doc!(title => "The Diary of a Young Girl"));
 ///         index_writer.commit().unwrap();
 ///     }
 ///     let reader = index.reader()?;
 ///     let searcher = reader.searcher();
-///
-///     {
-///
-///         let term = Term::from_field_text(title, "Diary");
-///         let query = FuzzyTermQuery::new(term, 1, true);
-///         let (top_docs, count) = searcher.search(&query, &(TopDocs::with_limit(2), Count)).unwrap();
-///         assert_eq!(count, 2);
-///         assert_eq!(top_docs.len(), 2);
-///     }
-///
+///     let term = Term::from_field_text(title, "Diary");
+///     let query = FuzzyTermQuery::new(term, 1, true);
+///     let (top_docs, count) = searcher.search(&query, &(TopDocs::with_limit(2), Count)).unwrap();
+///     assert_eq!(count, 2);
+///     assert_eq!(top_docs.len(), 2);
 ///     Ok(())
 /// }
 /// ```
@@ -76,54 +95,58 @@ static LEV_BUILDER: Lazy<HashMap<(u8, bool), LevenshteinAutomatonBuilder>> = Laz
 pub struct FuzzyTermQuery {
     /// What term are we searching
     term: Term,
-    /// How many changes are we going to allow
-    distance: u8,
-    /// Should a transposition cost 1 or 2?
-    transposition_cost_one: bool,
-    ///
-    prefix: bool,
+    configuration: FuzzyConfiguration
 }
 
 impl FuzzyTermQuery {
+    pub fn new_from_configuration(term: Term, configuration: FuzzyConfiguration) -> FuzzyTermQuery {
+        FuzzyTermQuery {
+            term,
+            configuration
+        }
+    }
+
     /// Creates a new Fuzzy Query
     pub fn new(term: Term, distance: u8, transposition_cost_one: bool) -> FuzzyTermQuery {
         FuzzyTermQuery {
             term,
-            distance,
-            transposition_cost_one,
-            prefix: false,
-        }
-    }
-
-    /// Creates a new Fuzzy Query that treats transpositions as cost one rather than two
-    pub fn new_prefix(term: Term, distance: u8, transposition_cost_one: bool) -> FuzzyTermQuery {
-        FuzzyTermQuery {
-            term,
-            distance,
-            transposition_cost_one,
-            prefix: true,
-        }
-    }
-
-    fn specialized_weight(&self) -> Result<AutomatonWeight<DFA>> {
-        // LEV_BUILDER is a HashMap, whose `get` method returns an Option
-        match LEV_BUILDER.get(&(self.distance, false)) {
-            // Unwrap the option and build the Ok(AutomatonWeight)
-            Some(automaton_builder) => {
-                let automaton = automaton_builder.build_dfa(self.term.text());
-                Ok(AutomatonWeight::new(self.term.field(), automaton))
+            configuration: FuzzyConfiguration {
+                distance,
+                transposition_cost_one,
+                prefix: false,
+                exact_distance: false
             }
-            None => Err(InvalidArgument(format!(
-                "Levenshtein distance of {} is not allowed. Choose a value in the {:?} range",
-                self.distance, VALID_LEVENSHTEIN_DISTANCE_RANGE
-            ))),
         }
     }
 }
 
 impl Query for FuzzyTermQuery {
     fn weight(&self, _searcher: &Searcher, _scoring_enabled: bool) -> Result<Box<dyn Weight>> {
-        Ok(Box::new(self.specialized_weight()?))
+        let dfa = build_dfa(&self.configuration, self.term.text())?;
+        // TODO optimize for distance = 0 and possibly prefix
+        if self.configuration.exact_distance {
+            let target_distance = self.configuration.distance;
+            let wrapped_dfa = WrappedDFA {
+                dfa,
+                condition: move |distance: Distance| distance == Distance::Exact(target_distance),
+            };
+            Ok(Box::new(AutomatonWeight::new(
+                self.term.field(),
+                wrapped_dfa,
+            )))
+        } else {
+            let wrapped_dfa = WrappedDFA {
+                dfa,
+                condition: move |distance: Distance| match distance {
+                    Distance::Exact(_) => true,
+                    Distance::AtLeast(_) => false,
+                },
+            };
+            Ok(Box::new(AutomatonWeight::new(
+                self.term.field(),
+                wrapped_dfa,
+            )))
+        }
     }
 }
 
@@ -136,6 +159,7 @@ mod test {
     use crate::tests::assert_nearly_equals;
     use crate::Index;
     use crate::Term;
+    use super::FuzzyConfigurationBuilder;
 
     #[test]
     pub fn test_fuzzy_term() {
@@ -157,7 +181,6 @@ mod test {
         let searcher = reader.searcher();
         {
             let term = Term::from_field_text(country_field, "japon");
-
             let fuzzy_query = FuzzyTermQuery::new(term, 1, true);
             let top_docs = searcher
                 .search(&fuzzy_query, &TopDocs::with_limit(2))
@@ -166,5 +189,73 @@ mod test {
             let (score, _) = top_docs[0];
             assert_nearly_equals(1f32, score);
         }
+        {
+            let term = Term::from_field_text(country_field, "japon");
+            let fuzzy_conf = FuzzyConfigurationBuilder::default()
+                .distance(2)
+                .exact_distance(true)
+                .build()
+                .unwrap();
+            let fuzzy_query = FuzzyTermQuery::new_from_configuration(term, fuzzy_conf);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert!(top_docs.is_empty());
+        }
+        {
+            let term = Term::from_field_text(country_field, "japon");
+            let fuzzy_conf = FuzzyConfigurationBuilder::default()
+                .distance(1)
+                .exact_distance(true)
+                .build()
+                .unwrap();
+            let fuzzy_query = FuzzyTermQuery::new_from_configuration(term, fuzzy_conf);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert_eq!(top_docs.len(), 1);
+        }
+        {
+            let term = Term::from_field_text(country_field, "jpp");
+            let fuzzy_conf = FuzzyConfigurationBuilder::default()
+                .distance(1)
+                .prefix(true)
+                .build()
+                .unwrap();
+            let fuzzy_query = FuzzyTermQuery::new_from_configuration(term, fuzzy_conf);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert_eq!(top_docs.len(), 1);
+        }
+        {
+            let term = Term::from_field_text(country_field, "jpaan");
+            let fuzzy_conf = FuzzyConfigurationBuilder::default()
+                .distance(1)
+                .exact_distance(true)
+                .transposition_cost_one(true)
+                .build()
+                .unwrap();
+            let fuzzy_query = FuzzyTermQuery::new_from_configuration(term, fuzzy_conf);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert_eq!(top_docs.len(), 1);
+        }
+        {
+            let term = Term::from_field_text(country_field, "jpaan");
+            let fuzzy_conf = FuzzyConfigurationBuilder::default()
+                .distance(2)
+                .exact_distance(true)
+                .transposition_cost_one(false)
+                .build()
+                .unwrap();
+            let fuzzy_query = FuzzyTermQuery::new_from_configuration(term, fuzzy_conf);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert_eq!(top_docs.len(), 1);
+        }
     }
+
 }

src/query/mod.rs

@@ -12,7 +12,6 @@ mod exclude;
 mod explanation;
 mod fuzzy_query;
 mod intersection;
-mod occur;
 mod phrase_query;
 mod query;
 mod query_parser;
@@ -41,9 +40,8 @@ pub use self::boolean_query::BooleanQuery;
 pub use self::empty_query::{EmptyQuery, EmptyScorer, EmptyWeight};
 pub use self::exclude::Exclude;
 pub use self::explanation::Explanation;
-pub use self::fuzzy_query::FuzzyTermQuery;
+pub use self::fuzzy_query::{FuzzyTermQuery, FuzzyConfiguration, FuzzyConfigurationBuilder};
 pub use self::intersection::intersect_scorers;
-pub use self::occur::Occur;
 pub use self::phrase_query::PhraseQuery;
 pub use self::query::Query;
 pub use self::query_parser::QueryParser;
@@ -55,6 +53,7 @@ pub use self::scorer::ConstScorer;
 pub use self::scorer::Scorer;
 pub use self::term_query::TermQuery;
 pub use self::weight::Weight;
+pub use tantivy_query_grammar::Occur;
 
 #[cfg(test)]
 mod tests {

src/query/query_parser/mod.rs

@@ -1,6 +1,4 @@
-mod query_grammar;
 mod query_parser;
-mod user_input_ast;
 
 pub mod logical_ast;
 pub use self::query_parser::QueryParser;

src/query/query_parser/query_parser.rs

@@ -1,9 +1,5 @@
 use super::logical_ast::*;
-use super::query_grammar::parse_to_ast;
-use super::user_input_ast::*;
 use crate::core::Index;
-use crate::query::occur::compose_occur;
-use crate::query::query_parser::logical_ast::LogicalAST;
 use crate::query::AllQuery;
 use crate::query::BooleanQuery;
 use crate::query::EmptyQuery;
@@ -16,11 +12,11 @@ use crate::schema::IndexRecordOption;
 use crate::schema::{Field, Schema};
 use crate::schema::{FieldType, Term};
 use crate::tokenizer::TokenizerManager;
-use combine::Parser;
 use std::borrow::Cow;
 use std::num::{ParseFloatError, ParseIntError};
 use std::ops::Bound;
 use std::str::FromStr;
+use tantivy_query_grammar::{UserInputAST, UserInputBound, UserInputLeaf};
 
 /// Possible error that may happen when parsing a query.
 #[derive(Debug, PartialEq, Eq, Fail)]
@@ -222,9 +218,8 @@ impl QueryParser {
 
     /// Parse the user query into an AST.
     fn parse_query_to_logical_ast(&self, query: &str) -> Result<LogicalAST, QueryParserError> {
-        let (user_input_ast, _remaining) = parse_to_ast()
-            .parse(query)
-            .map_err(|_| QueryParserError::SyntaxError)?;
+        let user_input_ast =
+            tantivy_query_grammar::parse_query(query).map_err(|_| QueryParserError::SyntaxError)?;
         self.compute_logical_ast(user_input_ast)
     }
 
@@ -369,6 +364,7 @@ impl QueryParser {
         match *bound {
             UserInputBound::Inclusive(_) => Ok(Bound::Included(term)),
             UserInputBound::Exclusive(_) => Ok(Bound::Excluded(term)),
+            UserInputBound::Unbounded => Ok(Bound::Unbounded),
         }
     }
 
@@ -398,7 +394,7 @@ impl QueryParser {
                 let mut logical_sub_queries: Vec<(Occur, LogicalAST)> = Vec::new();
                 for sub_query in sub_queries {
                     let (occur, sub_ast) = self.compute_logical_ast_with_occur(sub_query)?;
-                    let new_occur = compose_occur(default_occur, occur);
+                    let new_occur = Occur::compose(default_occur, occur);
                     logical_sub_queries.push((new_occur, sub_ast));
                 }
                 Ok((Occur::Should, LogicalAST::Clause(logical_sub_queries)))
@@ -406,7 +402,7 @@ impl QueryParser {
             UserInputAST::Unary(left_occur, subquery) => {
                 let (right_occur, logical_sub_queries) =
                     self.compute_logical_ast_with_occur(*subquery)?;
-                Ok((compose_occur(left_occur, right_occur), logical_sub_queries))
+                Ok((Occur::compose(left_occur, right_occur), logical_sub_queries))
             }
             UserInputAST::Leaf(leaf) => {
                 let result_ast = self.compute_logical_ast_from_leaf(*leaf)?;
@@ -628,7 +624,7 @@ mod test {
     pub fn test_parse_query_untokenized() {
         test_parse_query_to_logical_ast_helper(
             "nottokenized:\"wordone wordtwo\"",
-            "Term([0, 0, 0, 7, 119, 111, 114, 100, 111, 110, \
+            "Term(field=7,bytes=[119, 111, 114, 100, 111, 110, \
              101, 32, 119, 111, 114, 100, 116, 119, 111])",
             false,
         );
@@ -672,7 +668,7 @@ mod test {
             .is_ok());
         test_parse_query_to_logical_ast_helper(
             "unsigned:2324",
-            "Term([0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 9, 20])",
+            "Term(field=3,bytes=[0, 0, 0, 0, 0, 0, 9, 20])",
             false,
         );
 
@@ -693,19 +689,19 @@ mod test {
     pub fn test_parse_query_to_ast_single_term() {
         test_parse_query_to_logical_ast_helper(
             "title:toto",
-            "Term([0, 0, 0, 0, 116, 111, 116, 111])",
+            "Term(field=0,bytes=[116, 111, 116, 111])",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "+title:toto",
-            "Term([0, 0, 0, 0, 116, 111, 116, 111])",
+            "Term(field=0,bytes=[116, 111, 116, 111])",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "+title:toto -titi",
-            "(+Term([0, 0, 0, 0, 116, 111, 116, 111]) \
-             -(Term([0, 0, 0, 0, 116, 105, 116, 105]) \
-             Term([0, 0, 0, 1, 116, 105, 116, 105])))",
+            "(+Term(field=0,bytes=[116, 111, 116, 111]) \
+             -(Term(field=0,bytes=[116, 105, 116, 105]) \
+             Term(field=1,bytes=[116, 105, 116, 105])))",
             false,
         );
         assert_eq!(
@@ -720,14 +716,13 @@ mod test {
     pub fn test_parse_query_to_ast_two_terms() {
         test_parse_query_to_logical_ast_helper(
             "title:a b",
-            "(Term([0, 0, 0, 0, 97]) (Term([0, 0, 0, 0, 98]) \
-             Term([0, 0, 0, 1, 98])))",
+            "(Term(field=0,bytes=[97]) (Term(field=0,bytes=[98]) Term(field=1,bytes=[98])))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "title:\"a b\"",
-            "\"[(0, Term([0, 0, 0, 0, 97])), \
-             (1, Term([0, 0, 0, 0, 98]))]\"",
+            "\"[(0, Term(field=0,bytes=[97])), \
+             (1, Term(field=0,bytes=[98]))]\"",
             false,
         );
     }
@@ -736,45 +731,43 @@ mod test {
     pub fn test_parse_query_to_ast_ranges() {
         test_parse_query_to_logical_ast_helper(
             "title:[a TO b]",
-            "(Included(Term([0, 0, 0, 0, 97])) TO \
-             Included(Term([0, 0, 0, 0, 98])))",
+            "(Included(Term(field=0,bytes=[97])) TO Included(Term(field=0,bytes=[98])))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "[a TO b]",
-            "((Included(Term([0, 0, 0, 0, 97])) TO \
-             Included(Term([0, 0, 0, 0, 98]))) \
-             (Included(Term([0, 0, 0, 1, 97])) TO \
-             Included(Term([0, 0, 0, 1, 98]))))",
+            "((Included(Term(field=0,bytes=[97])) TO \
+             Included(Term(field=0,bytes=[98]))) \
+             (Included(Term(field=1,bytes=[97])) TO \
+             Included(Term(field=1,bytes=[98]))))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "title:{titi TO toto}",
-            "(Excluded(Term([0, 0, 0, 0, 116, 105, 116, 105])) TO \
-             Excluded(Term([0, 0, 0, 0, 116, 111, 116, 111])))",
+            "(Excluded(Term(field=0,bytes=[116, 105, 116, 105])) TO \
+             Excluded(Term(field=0,bytes=[116, 111, 116, 111])))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "title:{* TO toto}",
-            "(Unbounded TO \
-             Excluded(Term([0, 0, 0, 0, 116, 111, 116, 111])))",
+            "(Unbounded TO Excluded(Term(field=0,bytes=[116, 111, 116, 111])))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "title:{titi TO *}",
-            "(Excluded(Term([0, 0, 0, 0, 116, 105, 116, 105])) TO Unbounded)",
+            "(Excluded(Term(field=0,bytes=[116, 105, 116, 105])) TO Unbounded)",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "signed:{-5 TO 3}",
-            "(Excluded(Term([0, 0, 0, 2, 127, 255, 255, 255, 255, 255, 255, 251])) TO \
-            Excluded(Term([0, 0, 0, 2, 128, 0, 0, 0, 0, 0, 0, 3])))",
+            "(Excluded(Term(field=2,bytes=[127, 255, 255, 255, 255, 255, 255, 251])) TO \
+             Excluded(Term(field=2,bytes=[128, 0, 0, 0, 0, 0, 0, 3])))",
             false,
         );
         test_parse_query_to_logical_ast_helper(
             "float:{-1.5 TO 1.5}",
-            "(Excluded(Term([0, 0, 0, 10, 64, 7, 255, 255, 255, 255, 255, 255])) TO \
-            Excluded(Term([0, 0, 0, 10, 191, 248, 0, 0, 0, 0, 0, 0])))",
+            "(Excluded(Term(field=10,bytes=[64, 7, 255, 255, 255, 255, 255, 255])) TO \
+             Excluded(Term(field=10,bytes=[191, 248, 0, 0, 0, 0, 0, 0])))",
             false,
         );
 
@@ -879,19 +872,19 @@ mod test {
     pub fn test_parse_query_to_ast_conjunction() {
         test_parse_query_to_logical_ast_helper(
             "title:toto",
-            "Term([0, 0, 0, 0, 116, 111, 116, 111])",
+            "Term(field=0,bytes=[116, 111, 116, 111])",
             true,
         );
         test_parse_query_to_logical_ast_helper(
             "+title:toto",
-            "Term([0, 0, 0, 0, 116, 111, 116, 111])",
+            "Term(field=0,bytes=[116, 111, 116, 111])",
             true,
         );
         test_parse_query_to_logical_ast_helper(
             "+title:toto -titi",
-            "(+Term([0, 0, 0, 0, 116, 111, 116, 111]) \
-             -(Term([0, 0, 0, 0, 116, 105, 116, 105]) \
-             Term([0, 0, 0, 1, 116, 105, 116, 105])))",
+            "(+Term(field=0,bytes=[116, 111, 116, 111]) \
+             -(Term(field=0,bytes=[116, 105, 116, 105]) \
+             Term(field=1,bytes=[116, 105, 116, 105])))",
             true,
         );
         assert_eq!(
@@ -902,15 +895,15 @@ mod test {
         );
         test_parse_query_to_logical_ast_helper(
             "title:a b",
-            "(+Term([0, 0, 0, 0, 97]) \
-             +(Term([0, 0, 0, 0, 98]) \
-             Term([0, 0, 0, 1, 98])))",
+            "(+Term(field=0,bytes=[97]) \
+             +(Term(field=0,bytes=[98]) \
+             Term(field=1,bytes=[98])))",
             true,
         );
         test_parse_query_to_logical_ast_helper(
             "title:\"a b\"",
-            "\"[(0, Term([0, 0, 0, 0, 97])), \
-             (1, Term([0, 0, 0, 0, 98]))]\"",
+            "\"[(0, Term(field=0,bytes=[97])), \
+             (1, Term(field=0,bytes=[98]))]\"",
             true,
         );
     }
@@ -919,10 +912,8 @@ mod test {
     pub fn test_query_parser_hyphen() {
         test_parse_query_to_logical_ast_helper(
             "title:www-form-encoded",
-            "\"[(0, Term([0, 0, 0, 0, 119, 119, 119])), \
-             (1, Term([0, 0, 0, 0, 102, 111, 114, 109])), \
-             (2, Term([0, 0, 0, 0, 101, 110, 99, 111, 100, 101, 100]))]\"",
-            false,
+            "\"[(0, Term(field=0,bytes=[119, 119, 119])), (1, Term(field=0,bytes=[102, 111, 114, 109])), (2, Term(field=0,bytes=[101, 110, 99, 111, 100, 101, 100]))]\"",
+            false
         );
     }
 }

src/query/range_query.rs

@@ -38,14 +38,10 @@ fn map_bound<TFrom, TTo, Transform: Fn(&TFrom) -> TTo>(
 /// # Example
 ///
 /// ```rust
-///
-/// # #[macro_use]
-/// # extern crate tantivy;
-/// # use tantivy::Index;
-/// # use tantivy::schema::{Schema, INDEXED};
 /// # use tantivy::collector::Count;
-/// # use tantivy::Result;
 /// # use tantivy::query::RangeQuery;
+/// # use tantivy::schema::{Schema, INDEXED};
+/// # use tantivy::{doc, Index, Result};
 /// #
 /// # fn run() -> Result<()> {
 /// #     let mut schema_builder = Schema::builder();
@@ -338,39 +334,33 @@ mod tests {
     use crate::collector::Count;
     use crate::schema::{Document, Field, Schema, INDEXED};
     use crate::Index;
-    use crate::Result;
     use std::collections::Bound;
 
     #[test]
     fn test_range_query_simple() {
-        fn run() -> Result<()> {
-            let mut schema_builder = Schema::builder();
-            let year_field = schema_builder.add_u64_field("year", INDEXED);
-            let schema = schema_builder.build();
+        let mut schema_builder = Schema::builder();
+        let year_field = schema_builder.add_u64_field("year", INDEXED);
+        let schema = schema_builder.build();
 
-            let index = Index::create_in_ram(schema);
-            {
-                let mut index_writer = index.writer_with_num_threads(1, 6_000_000).unwrap();
-                for year in 1950u64..2017u64 {
-                    let num_docs_within_year = 10 + (year - 1950) * (year - 1950);
-                    for _ in 0..num_docs_within_year {
-                        index_writer.add_document(doc!(year_field => year));
-                    }
+        let index = Index::create_in_ram(schema);
+        {
+            let mut index_writer = index.writer_with_num_threads(1, 6_000_000).unwrap();
+            for year in 1950u64..2017u64 {
+                let num_docs_within_year = 10 + (year - 1950) * (year - 1950);
+                for _ in 0..num_docs_within_year {
+                    index_writer.add_document(doc!(year_field => year));
                 }
-                index_writer.commit().unwrap();
             }
-            let reader = index.reader().unwrap();
-            let searcher = reader.searcher();
-
-            let docs_in_the_sixties = RangeQuery::new_u64(year_field, 1960u64..1970u64);
-
-            // ... or `1960..=1969` if inclusive range is enabled.
-            let count = searcher.search(&docs_in_the_sixties, &Count)?;
-            assert_eq!(count, 2285);
-            Ok(())
+            index_writer.commit().unwrap();
         }
+        let reader = index.reader().unwrap();
+        let searcher = reader.searcher();
 
-        run().unwrap();
+        let docs_in_the_sixties = RangeQuery::new_u64(year_field, 1960u64..1970u64);
+
+        // ... or `1960..=1969` if inclusive range is enabled.
+        let count = searcher.search(&docs_in_the_sixties, &Count).unwrap();
+        assert_eq!(count, 2285);
     }
 
     #[test]

src/query/regex_query.rs

@@ -4,22 +4,18 @@ use crate::schema::Field;
 use crate::Result;
 use crate::Searcher;
 use std::clone::Clone;
+use std::sync::Arc;
 use tantivy_fst::Regex;
 
-// A Regex Query matches all of the documents
+/// A Regex Query matches all of the documents
 /// containing a specific term that matches
-/// a regex pattern
-/// A Fuzzy Query matches all of the documents
-/// containing a specific term that is within
-/// Levenshtein distance
+/// a regex pattern.
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Schema, TEXT};
-/// use tantivy::{Index, Result, Term};
 /// use tantivy::collector::Count;
 /// use tantivy::query::RegexQuery;
+/// use tantivy::schema::{Schema, TEXT};
+/// use tantivy::{doc, Index, Result, Term};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {
@@ -48,7 +44,7 @@ use tantivy_fst::Regex;
 ///     let searcher = reader.searcher();
 ///
 ///     let term = Term::from_field_text(title, "Diary");
-///     let query = RegexQuery::new("d[ai]{2}ry".to_string(), title);
+///     let query = RegexQuery::from_pattern("d[ai]{2}ry", title)?;
 ///     let count = searcher.search(&query, &Count)?;
 ///     assert_eq!(count, 3);
 ///     Ok(())
@@ -56,30 +52,34 @@ use tantivy_fst::Regex;
 /// ```
 #[derive(Debug, Clone)]
 pub struct RegexQuery {
-    regex_pattern: String,
+    regex: Arc<Regex>,
     field: Field,
 }
 
 impl RegexQuery {
-    /// Creates a new Fuzzy Query
-    pub fn new(regex_pattern: String, field: Field) -> RegexQuery {
+    /// Creates a new RegexQuery from a given pattern
+    pub fn from_pattern(regex_pattern: &str, field: Field) -> Result<Self> {
+        let regex = Regex::new(&regex_pattern)
+            .map_err(|_| TantivyError::InvalidArgument(regex_pattern.to_string()))?;
+        Ok(RegexQuery::from_regex(regex, field))
+    }
+
+    /// Creates a new RegexQuery from a fully built Regex
+    pub fn from_regex<T: Into<Arc<Regex>>>(regex: T, field: Field) -> Self {
         RegexQuery {
-            regex_pattern,
+            regex: regex.into(),
             field,
         }
     }
 
-    fn specialized_weight(&self) -> Result<AutomatonWeight<Regex>> {
-        let automaton = Regex::new(&self.regex_pattern)
-            .map_err(|_| TantivyError::InvalidArgument(self.regex_pattern.clone()))?;
-
-        Ok(AutomatonWeight::new(self.field, automaton))
+    fn specialized_weight(&self) -> AutomatonWeight<Regex> {
+        AutomatonWeight::new(self.field, self.regex.clone())
     }
 }
 
 impl Query for RegexQuery {
     fn weight(&self, _searcher: &Searcher, _scoring_enabled: bool) -> Result<Box<dyn Weight>> {
-        Ok(Box::new(self.specialized_weight()?))
+        Ok(Box::new(self.specialized_weight()))
     }
 }
 
@@ -87,13 +87,14 @@ impl Query for RegexQuery {
 mod test {
     use super::RegexQuery;
     use crate::collector::TopDocs;
-    use crate::schema::Schema;
     use crate::schema::TEXT;
+    use crate::schema::{Field, Schema};
     use crate::tests::assert_nearly_equals;
-    use crate::Index;
+    use crate::{Index, IndexReader};
+    use std::sync::Arc;
+    use tantivy_fst::Regex;
 
-    #[test]
-    pub fn test_regex_query() {
+    fn build_test_index() -> (IndexReader, Field) {
         let mut schema_builder = Schema::builder();
         let country_field = schema_builder.add_text_field("country", TEXT);
         let schema = schema_builder.build();
@@ -109,20 +110,65 @@ mod test {
             index_writer.commit().unwrap();
         }
         let reader = index.reader().unwrap();
+
+        (reader, country_field)
+    }
+
+    fn verify_regex_query(
+        query_matching_one: RegexQuery,
+        query_matching_zero: RegexQuery,
+        reader: IndexReader,
+    ) {
         let searcher = reader.searcher();
         {
-            let regex_query = RegexQuery::new("jap[ao]n".to_string(), country_field);
             let scored_docs = searcher
-                .search(&regex_query, &TopDocs::with_limit(2))
+                .search(&query_matching_one, &TopDocs::with_limit(2))
                 .unwrap();
             assert_eq!(scored_docs.len(), 1, "Expected only 1 document");
             let (score, _) = scored_docs[0];
             assert_nearly_equals(1f32, score);
         }
-        let regex_query = RegexQuery::new("jap[A-Z]n".to_string(), country_field);
         let top_docs = searcher
-            .search(&regex_query, &TopDocs::with_limit(2))
+            .search(&query_matching_zero, &TopDocs::with_limit(2))
             .unwrap();
         assert!(top_docs.is_empty(), "Expected ZERO document");
     }
+
+    #[test]
+    pub fn test_regex_query() {
+        let (reader, field) = build_test_index();
+
+        let matching_one = RegexQuery::from_pattern("jap[ao]n", field).unwrap();
+        let matching_zero = RegexQuery::from_pattern("jap[A-Z]n", field).unwrap();
+
+        verify_regex_query(matching_one, matching_zero, reader);
+    }
+
+    #[test]
+    pub fn test_construct_from_regex() {
+        let (reader, field) = build_test_index();
+
+        let matching_one = RegexQuery::from_regex(Regex::new("jap[ao]n").unwrap(), field);
+        let matching_zero = RegexQuery::from_regex(Regex::new("jap[A-Z]n").unwrap(), field);
+
+        verify_regex_query(matching_one, matching_zero, reader);
+    }
+
+    #[test]
+    pub fn test_construct_from_reused_regex() {
+        let r1 = Arc::new(Regex::new("jap[ao]n").unwrap());
+        let r2 = Arc::new(Regex::new("jap[A-Z]n").unwrap());
+
+        let (reader, field) = build_test_index();
+
+        let matching_one = RegexQuery::from_regex(r1.clone(), field);
+        let matching_zero = RegexQuery::from_regex(r2.clone(), field);
+
+        verify_regex_query(matching_one, matching_zero, reader.clone());
+
+        let matching_one = RegexQuery::from_regex(r1.clone(), field);
+        let matching_zero = RegexQuery::from_regex(r2.clone(), field);
+
+        verify_regex_query(matching_one, matching_zero, reader.clone());
+    }
 }

src/query/term_query/mod.rs

@@ -12,7 +12,7 @@ mod tests {
     use crate::collector::TopDocs;
     use crate::docset::DocSet;
     use crate::query::{Query, QueryParser, Scorer, TermQuery};
-    use crate::schema::{IndexRecordOption, Schema, STRING, TEXT};
+    use crate::schema::{Field, IndexRecordOption, Schema, STRING, TEXT};
     use crate::tests::assert_nearly_equals;
     use crate::Index;
     use crate::Term;
@@ -114,4 +114,16 @@ mod tests {
         let reader = index.reader().unwrap();
         assert_eq!(term_query.count(&*reader.searcher()).unwrap(), 1);
     }
+
+    #[test]
+    fn test_term_query_debug() {
+        let term_query = TermQuery::new(
+            Term::from_field_text(Field(1), "hello"),
+            IndexRecordOption::WithFreqs,
+        );
+        assert_eq!(
+            format!("{:?}", term_query),
+            "TermQuery(Term(field=1,bytes=[104, 101, 108, 108, 111]))"
+        );
+    }
 }

src/query/term_query/term_query.rs

@@ -7,6 +7,7 @@ use crate::Result;
 use crate::Searcher;
 use crate::Term;
 use std::collections::BTreeSet;
+use std::fmt;
 
 /// A Term query matches all of the documents
 /// containing a specific term.
@@ -19,12 +20,10 @@ use std::collections::BTreeSet;
 /// * `field norm` - number of tokens in the field.
 ///
 /// ```rust
-/// #[macro_use]
-/// extern crate tantivy;
-/// use tantivy::schema::{Schema, TEXT, IndexRecordOption};
-/// use tantivy::{Index, Result, Term};
 /// use tantivy::collector::{Count, TopDocs};
 /// use tantivy::query::TermQuery;
+/// use tantivy::schema::{Schema, TEXT, IndexRecordOption};
+/// use tantivy::{doc, Index, Result, Term};
 ///
 /// # fn main() { example().unwrap(); }
 /// fn example() -> Result<()> {
@@ -61,12 +60,18 @@ use std::collections::BTreeSet;
 ///     Ok(())
 /// }
 /// ```
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct TermQuery {
     term: Term,
     index_record_option: IndexRecordOption,
 }
 
+impl fmt::Debug for TermQuery {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "TermQuery({:?})", self.term)
+    }
+}
+
 impl TermQuery {
     /// Creates a new term query.
     pub fn new(term: Term, segment_postings_options: IndexRecordOption) -> TermQuery {

src/schema/field_type.rs

@@ -10,7 +10,7 @@ use serde_json::Value as JsonValue;
 
 /// Possible error that may occur while parsing a field value
 /// At this point the JSON is known to be valid.
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum ValueParsingError {
     /// Encountered a numerical value that overflows or underflow its integer type.
     OverflowError(String),

src/schema/schema.rs

@@ -246,6 +246,25 @@ impl Schema {
         self.0.fields_map.get(field_name).cloned()
     }
 
+    /// Create a named document off the doc.
+    pub fn convert_named_doc(
+        &self,
+        named_doc: NamedFieldDocument,
+    ) -> Result<Document, DocParsingError> {
+        let mut document = Document::new();
+        for (field_name, values) in named_doc.0 {
+            if let Some(field) = self.get_field(&field_name) {
+                for value in values {
+                    let field_value = FieldValue::new(field, value);
+                    document.add(field_value);
+                }
+            } else {
+                return Err(DocParsingError::NoSuchFieldInSchema(field_name));
+            }
+        }
+        Ok(document)
+    }
+
     /// Create a named document off the doc.
     pub fn to_named_doc(&self, doc: &Document) -> NamedFieldDocument {
         let mut field_map = BTreeMap::new();
@@ -282,28 +301,26 @@ impl Schema {
 
         let mut doc = Document::default();
         for (field_name, json_value) in json_obj.iter() {
-            match self.get_field(field_name) {
-                Some(field) => {
-                    let field_entry = self.get_field_entry(field);
-                    let field_type = field_entry.field_type();
-                    match *json_value {
-                        JsonValue::Array(ref json_items) => {
-                            for json_item in json_items {
-                                let value = field_type.value_from_json(json_item).map_err(|e| {
-                                    DocParsingError::ValueError(field_name.clone(), e)
-                                })?;
-                                doc.add(FieldValue::new(field, value));
-                            }
-                        }
-                        _ => {
-                            let value = field_type
-                                .value_from_json(json_value)
-                                .map_err(|e| DocParsingError::ValueError(field_name.clone(), e))?;
-                            doc.add(FieldValue::new(field, value));
-                        }
+            let field = self
+                .get_field(field_name)
+                .ok_or_else(|| DocParsingError::NoSuchFieldInSchema(field_name.clone()))?;
+            let field_entry = self.get_field_entry(field);
+            let field_type = field_entry.field_type();
+            match *json_value {
+                JsonValue::Array(ref json_items) => {
+                    for json_item in json_items {
+                        let value = field_type
+                            .value_from_json(json_item)
+                            .map_err(|e| DocParsingError::ValueError(field_name.clone(), e))?;
+                        doc.add(FieldValue::new(field, value));
                     }
                 }
-                None => return Err(DocParsingError::NoSuchFieldInSchema(field_name.clone())),
+                _ => {
+                    let value = field_type
+                        .value_from_json(json_value)
+                        .map_err(|e| DocParsingError::ValueError(field_name.clone(), e))?;
+                    doc.add(FieldValue::new(field, value));
+                }
             }
         }
         Ok(doc)
@@ -360,7 +377,7 @@ impl<'de> Deserialize<'de> for Schema {
 
 /// Error that may happen when deserializing
 /// a document from JSON.
-#[derive(Debug, Fail)]
+#[derive(Debug, Fail, PartialEq)]
 pub enum DocParsingError {
     /// The payload given is not valid JSON.
     #[fail(display = "The provided string is not valid JSON")]
@@ -369,7 +386,10 @@ pub enum DocParsingError {
     #[fail(display = "The field '{:?}' could not be parsed: {:?}", _0, _1)]
     ValueError(String, ValueParsingError),
     /// The json-document contains a field that is not declared in the schema.
-    #[fail(display = "The json-document contains an unknown field: {:?}", _0)]
+    #[fail(
+        display = "The document contains a field that is not declared in the schema: {:?}",
+        _0
+    )]
     NoSuchFieldInSchema(String),
 }
 
@@ -381,6 +401,7 @@ mod tests {
     use crate::schema::*;
     use matches::{assert_matches, matches};
     use serde_json;
+    use std::collections::BTreeMap;
 
     #[test]
     pub fn is_indexed_test() {
@@ -495,6 +516,54 @@ mod tests {
         assert_eq!(doc, doc_serdeser);
     }
 
+    #[test]
+    pub fn test_document_from_nameddoc() {
+        let mut schema_builder = Schema::builder();
+        let title = schema_builder.add_text_field("title", TEXT);
+        let val = schema_builder.add_i64_field("val", INDEXED);
+        let schema = schema_builder.build();
+        let mut named_doc_map = BTreeMap::default();
+        named_doc_map.insert(
+            "title".to_string(),
+            vec![Value::from("title1"), Value::from("title2")],
+        );
+        named_doc_map.insert(
+            "val".to_string(),
+            vec![Value::from(14u64), Value::from(-1i64)],
+        );
+        let doc = schema
+            .convert_named_doc(NamedFieldDocument(named_doc_map))
+            .unwrap();
+        assert_eq!(
+            doc.get_all(title),
+            vec![
+                &Value::from("title1".to_string()),
+                &Value::from("title2".to_string())
+            ]
+        );
+        assert_eq!(
+            doc.get_all(val),
+            vec![&Value::from(14u64), &Value::from(-1i64)]
+        );
+    }
+
+    #[test]
+    pub fn test_document_from_nameddoc_error() {
+        let schema = Schema::builder().build();
+        let mut named_doc_map = BTreeMap::default();
+        named_doc_map.insert(
+            "title".to_string(),
+            vec![Value::from("title1"), Value::from("title2")],
+        );
+        let err = schema
+            .convert_named_doc(NamedFieldDocument(named_doc_map))
+            .unwrap_err();
+        assert_eq!(
+            err,
+            DocParsingError::NoSuchFieldInSchema("title".to_string())
+        );
+    }
+
     #[test]
     pub fn test_parse_document() {
         let mut schema_builder = Schema::builder();

src/schema/term.rs

@@ -224,7 +224,12 @@ where
 
 impl fmt::Debug for Term {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "Term({:?})", &self.0[..])
+        write!(
+            f,
+            "Term(field={},bytes={:?})",
+            self.field().0,
+            self.value_bytes()
+        )
     }
 }
 

src/snippet/mod.rs

@@ -63,7 +63,7 @@ impl FragmentCandidate {
     fn try_add_token(&mut self, token: &Token, terms: &BTreeMap<String, f32>) {
         self.stop_offset = token.offset_to;
 
-        if let Some(score) = terms.get(&token.text.to_lowercase()) {
+        if let Some(&score) = terms.get(&token.text.to_lowercase()) {
             self.score += score;
             self.highlighted
                 .push(HighlightSection::new(token.offset_from, token.offset_to));
@@ -142,7 +142,7 @@ impl Snippet {
 /// Fragments must be valid in the sense that `&text[fragment.start..fragment.stop]`\
 /// has to be a valid string.
 fn search_fragments<'a>(
-    tokenizer: &dyn BoxedTokenizer,
+    tokenizer: &BoxedTokenizer,
     text: &'a str,
     terms: &BTreeMap<String, f32>,
     max_num_chars: usize,
@@ -150,7 +150,6 @@ fn search_fragments<'a>(
     let mut token_stream = tokenizer.token_stream(text);
     let mut fragment = FragmentCandidate::new(0);
     let mut fragments: Vec<FragmentCandidate> = vec![];
-
     while let Some(next) = token_stream.next() {
         if (next.offset_to - fragment.start_offset) > max_num_chars {
             if fragment.score > 0.0 {
@@ -214,11 +213,9 @@ fn select_best_fragment_combination(fragments: &[FragmentCandidate], text: &str)
 /// # Example
 ///
 /// ```rust
-/// # #[macro_use]
-/// # extern crate tantivy;
-/// # use tantivy::Index;
-/// # use tantivy::schema::{Schema, TEXT};
 /// # use tantivy::query::QueryParser;
+/// # use tantivy::schema::{Schema, TEXT};
+/// # use tantivy::{doc, Index};
 /// use tantivy::SnippetGenerator;
 ///
 /// # fn main() -> tantivy::Result<()> {
@@ -254,7 +251,7 @@ fn select_best_fragment_combination(fragments: &[FragmentCandidate], text: &str)
 /// ```
 pub struct SnippetGenerator {
     terms_text: BTreeMap<String, f32>,
-    tokenizer: Box<dyn BoxedTokenizer>,
+    tokenizer: BoxedTokenizer,
     field: Field,
     max_num_chars: usize,
 }
@@ -316,12 +313,8 @@ impl SnippetGenerator {
 
     /// Generates a snippet for the given text.
     pub fn snippet(&self, text: &str) -> Snippet {
-        let fragment_candidates = search_fragments(
-            &*self.tokenizer,
-            &text,
-            &self.terms_text,
-            self.max_num_chars,
-        );
+        let fragment_candidates =
+            search_fragments(&self.tokenizer, &text, &self.terms_text, self.max_num_chars);
         select_best_fragment_combination(&fragment_candidates[..], &text)
     }
 }
@@ -331,7 +324,7 @@ mod tests {
     use super::{search_fragments, select_best_fragment_combination};
     use crate::query::QueryParser;
     use crate::schema::{IndexRecordOption, Schema, TextFieldIndexing, TextOptions, TEXT};
-    use crate::tokenizer::{box_tokenizer, SimpleTokenizer};
+    use crate::tokenizer::SimpleTokenizer;
     use crate::Index;
     use crate::SnippetGenerator;
     use maplit::btreemap;
@@ -355,12 +348,12 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
         let terms = btreemap! {
             String::from("rust") => 1.0,
             String::from("language") => 0.9
         };
-        let fragments = search_fragments(&*boxed_tokenizer, TEST_TEXT, &terms, 100);
+        let fragments = search_fragments(&boxed_tokenizer, TEST_TEXT, &terms, 100);
         assert_eq!(fragments.len(), 7);
         {
             let first = &fragments[0];
@@ -382,13 +375,13 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_scored_fragment() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
         {
             let terms = btreemap! {
                 String::from("rust") =>1.0f32,
                 String::from("language") => 0.9f32
             };
-            let fragments = search_fragments(&*boxed_tokenizer, TEST_TEXT, &terms, 20);
+            let fragments = search_fragments(&boxed_tokenizer, TEST_TEXT, &terms, 20);
             {
                 let first = &fragments[0];
                 assert_eq!(first.score, 1.0);
@@ -397,13 +390,13 @@ Survey in 2016, 2017, and 2018."#;
             let snippet = select_best_fragment_combination(&fragments[..], &TEST_TEXT);
             assert_eq!(snippet.to_html(), "<b>Rust</b> is a systems")
         }
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
         {
             let terms = btreemap! {
                 String::from("rust") =>0.9f32,
                 String::from("language") => 1.0f32
             };
-            let fragments = search_fragments(&*boxed_tokenizer, TEST_TEXT, &terms, 20);
+            let fragments = search_fragments(&boxed_tokenizer, TEST_TEXT, &terms, 20);
             //assert_eq!(fragments.len(), 7);
             {
                 let first = &fragments[0];
@@ -417,14 +410,14 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_in_second_fragment() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
 
         let text = "a b c d e f g";
 
         let mut terms = BTreeMap::new();
         terms.insert(String::from("c"), 1.0);
 
-        let fragments = search_fragments(&*boxed_tokenizer, &text, &terms, 3);
+        let fragments = search_fragments(&boxed_tokenizer, &text, &terms, 3);
 
         assert_eq!(fragments.len(), 1);
         {
@@ -441,14 +434,14 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_with_term_at_the_end_of_fragment() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
 
         let text = "a b c d e f f g";
 
         let mut terms = BTreeMap::new();
         terms.insert(String::from("f"), 1.0);
 
-        let fragments = search_fragments(&*boxed_tokenizer, &text, &terms, 3);
+        let fragments = search_fragments(&boxed_tokenizer, &text, &terms, 3);
 
         assert_eq!(fragments.len(), 2);
         {
@@ -465,7 +458,7 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_with_second_fragment_has_the_highest_score() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
 
         let text = "a b c d e f g";
 
@@ -473,7 +466,7 @@ Survey in 2016, 2017, and 2018."#;
         terms.insert(String::from("f"), 1.0);
         terms.insert(String::from("a"), 0.9);
 
-        let fragments = search_fragments(&*boxed_tokenizer, &text, &terms, 7);
+        let fragments = search_fragments(&boxed_tokenizer, &text, &terms, 7);
 
         assert_eq!(fragments.len(), 2);
         {
@@ -490,14 +483,14 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_with_term_not_in_text() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
 
         let text = "a b c d";
 
         let mut terms = BTreeMap::new();
         terms.insert(String::from("z"), 1.0);
 
-        let fragments = search_fragments(&*boxed_tokenizer, &text, &terms, 3);
+        let fragments = search_fragments(&boxed_tokenizer, &text, &terms, 3);
 
         assert_eq!(fragments.len(), 0);
 
@@ -508,12 +501,12 @@ Survey in 2016, 2017, and 2018."#;
 
     #[test]
     fn test_snippet_with_no_terms() {
-        let boxed_tokenizer = box_tokenizer(SimpleTokenizer);
+        let boxed_tokenizer = SimpleTokenizer.into();
 
         let text = "a b c d";
 
         let terms = BTreeMap::new();
-        let fragments = search_fragments(&*boxed_tokenizer, &text, &terms, 3);
+        let fragments = search_fragments(&boxed_tokenizer, &text, &terms, 3);
         assert_eq!(fragments.len(), 0);
 
         let snippet = select_best_fragment_combination(&fragments[..], &text);

src/termdict/mod.rs

@@ -31,14 +31,43 @@ mod termdict;
 pub use self::merger::TermMerger;
 pub use self::streamer::{TermStreamer, TermStreamerBuilder};
 pub use self::termdict::{TermDictionary, TermDictionaryBuilder};
+use levenshtein_automata::{Distance, DFA, SINK_STATE};
+use tantivy_fst::Automaton;
+
+pub(crate) struct WrappedDFA<Cond> {
+    pub dfa: DFA,
+    pub condition: Cond,
+}
+
+impl<Cond: Fn(Distance) -> bool> Automaton for WrappedDFA<Cond> {
+    type State = u32;
+
+    fn start(&self) -> Self::State {
+        self.dfa.initial_state()
+    }
+
+    fn is_match(&self, state: &Self::State) -> bool {
+        let distance = self.dfa.distance(*state);
+        (self.condition)(distance)
+    }
+
+    fn can_match(&self, state: &Self::State) -> bool {
+        *state != SINK_STATE
+    }
+
+    fn accept(&self, state: &Self::State, byte: u8) -> Self::State {
+        self.dfa.transition(*state, byte)
+    }
+}
 
 #[cfg(test)]
 mod tests {
-    use super::{TermDictionary, TermDictionaryBuilder, TermStreamer};
+    use super::{TermDictionary, TermDictionaryBuilder, TermStreamer, WrappedDFA};
     use crate::core::Index;
     use crate::directory::{Directory, RAMDirectory, ReadOnlySource};
     use crate::postings::TermInfo;
     use crate::schema::{Document, FieldType, Schema, TEXT};
+    use levenshtein_automata::Distance;
     use std::path::PathBuf;
     use std::str;
 
@@ -423,9 +452,14 @@ mod tests {
 
         // We can now build an entire dfa.
         let lev_automaton_builder = LevenshteinAutomatonBuilder::new(2, true);
-        let automaton = lev_automaton_builder.build_dfa("Spaen");
-
-        let mut range = term_dict.search(automaton).into_stream();
+        let wrapped_dfa = WrappedDFA {
+            dfa: lev_automaton_builder.build_dfa("Spaen"),
+            condition: |distance| match distance {
+                Distance::Exact(_) => true,
+                Distance::AtLeast(_) => false,
+            },
+        };
+        let mut range = term_dict.search(wrapped_dfa).into_stream();
 
         // get the first finding
         assert!(range.advance());

src/tokenizer/alphanum_only.rs

@@ -1,6 +1,5 @@
 //! # Example
-//! ```
-//! extern crate tantivy;
+//! ```rust
 //! use tantivy::tokenizer::*;
 //!
 //! # fn main() {

src/tokenizer/mod.rs

@@ -4,8 +4,7 @@
 //! You must define in your schema which tokenizer should be used for
 //! each of your fields :
 //!
-//! ```
-//! extern crate tantivy;
+//! ```rust
 //! use tantivy::schema::*;
 //!
 //! # fn main() {
@@ -65,8 +64,6 @@
 //! For instance, the `en_stem` is defined as follows.
 //!
 //! ```rust
-//! # extern crate tantivy;
-//!
 //! use tantivy::tokenizer::*;
 //!
 //! # fn main() {
@@ -80,8 +77,7 @@
 //! Once your tokenizer is defined, you need to
 //! register it with a name in your index's [`TokenizerManager`](./struct.TokenizerManager.html).
 //!
-//! ```
-//! # extern crate tantivy;
+//! ```rust
 //! # use tantivy::schema::Schema;
 //! # use tantivy::tokenizer::*;
 //! # use tantivy::Index;
@@ -101,8 +97,7 @@
 //!
 //! # Example
 //!
-//! ```
-//! extern crate tantivy;
+//! ```rust
 //! use tantivy::schema::{Schema, IndexRecordOption, TextOptions, TextFieldIndexing};
 //! use tantivy::tokenizer::*;
 //! use tantivy::Index;
@@ -155,7 +150,6 @@ pub use self::simple_tokenizer::SimpleTokenizer;
 pub use self::stemmer::{Language, Stemmer};
 pub use self::stop_word_filter::StopWordFilter;
 pub(crate) use self::token_stream_chain::TokenStreamChain;
-pub(crate) use self::tokenizer::box_tokenizer;
 pub use self::tokenizer::BoxedTokenizer;
 
 pub use self::tokenizer::{Token, TokenFilter, TokenStream, Tokenizer};

src/tokenizer/ngram_tokenizer.rs

@@ -29,8 +29,7 @@ use super::{Token, TokenStream, Tokenizer};
 ///
 /// # Example
 ///
-/// ```
-/// # extern crate tantivy;
+/// ```rust
 /// use tantivy::tokenizer::*;
 /// # fn main() {
 /// let tokenizer = NgramTokenizer::new(2, 3, false);

src/tokenizer/remove_long.rs

@@ -1,6 +1,5 @@
 //! # Example
-//! ```
-//! extern crate tantivy;
+//! ```rust
 //! use tantivy::tokenizer::*;
 //!
 //! # fn main() {

src/tokenizer/stop_word_filter.rs

@@ -1,6 +1,5 @@
 //! # Example
-//! ```
-//! extern crate tantivy;
+//! ```rust
 //! use tantivy::tokenizer::*;
 //!
 //! # fn main() {

src/tokenizer/tokenizer.rs

@@ -56,8 +56,6 @@ pub trait Tokenizer<'a>: Sized + Clone {
     /// # Example
     ///
     /// ```rust
-    /// # extern crate tantivy;
-    ///
     /// use tantivy::tokenizer::*;
     ///
     /// # fn main() {
@@ -80,7 +78,7 @@ pub trait Tokenizer<'a>: Sized + Clone {
 }
 
 /// A boxed tokenizer
-pub trait BoxedTokenizer: Send + Sync {
+trait BoxedTokenizerTrait: Send + Sync {
     /// Tokenize a `&str`
     fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a>;
 
@@ -92,7 +90,41 @@ pub trait BoxedTokenizer: Send + Sync {
     fn token_stream_texts<'b>(&self, texts: &'b [&'b str]) -> Box<dyn TokenStream + 'b>;
 
     /// Return a boxed clone of the tokenizer
-    fn boxed_clone(&self) -> Box<dyn BoxedTokenizer>;
+    fn boxed_clone(&self) -> BoxedTokenizer;
+}
+
+/// A boxed tokenizer
+pub struct BoxedTokenizer(Box<dyn BoxedTokenizerTrait>);
+
+impl<T> From<T> for BoxedTokenizer
+where
+    T: 'static + Send + Sync + for<'a> Tokenizer<'a>,
+{
+    fn from(tokenizer: T) -> BoxedTokenizer {
+        BoxedTokenizer(Box::new(BoxableTokenizer(tokenizer)))
+    }
+}
+
+impl BoxedTokenizer {
+    /// Tokenize a `&str`
+    pub fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
+        self.0.token_stream(text)
+    }
+
+    /// Tokenize an array`&str`
+    ///
+    /// The resulting `TokenStream` is equivalent to what would be obtained if the &str were
+    /// one concatenated `&str`, with an artificial position gap of `2` between the different fields
+    /// to prevent accidental `PhraseQuery` to match accross two terms.
+    pub fn token_stream_texts<'b>(&self, texts: &'b [&'b str]) -> Box<dyn TokenStream + 'b> {
+        self.0.token_stream_texts(texts)
+    }
+}
+
+impl Clone for BoxedTokenizer {
+    fn clone(&self) -> BoxedTokenizer {
+        self.0.boxed_clone()
+    }
 }
 
 #[derive(Clone)]
@@ -100,7 +132,7 @@ struct BoxableTokenizer<A>(A)
 where
     A: for<'a> Tokenizer<'a> + Send + Sync;
 
-impl<A> BoxedTokenizer for BoxableTokenizer<A>
+impl<A> BoxedTokenizerTrait for BoxableTokenizer<A>
 where
     A: 'static + Send + Sync + for<'a> Tokenizer<'a>,
 {
@@ -125,18 +157,11 @@ where
         }
     }
 
-    fn boxed_clone(&self) -> Box<dyn BoxedTokenizer> {
-        Box::new(self.clone())
+    fn boxed_clone(&self) -> BoxedTokenizer {
+        self.0.clone().into()
     }
 }
 
-pub(crate) fn box_tokenizer<A>(a: A) -> Box<dyn BoxedTokenizer>
-where
-    A: 'static + Send + Sync + for<'a> Tokenizer<'a>,
-{
-    Box::new(BoxableTokenizer(a))
-}
-
 impl<'b> TokenStream for Box<dyn TokenStream + 'b> {
     fn advance(&mut self) -> bool {
         let token_stream: &mut dyn TokenStream = self.borrow_mut();
@@ -161,7 +186,6 @@ impl<'b> TokenStream for Box<dyn TokenStream + 'b> {
 /// # Example
 ///
 /// ```
-/// extern crate tantivy;
 /// use tantivy::tokenizer::*;
 ///
 /// # fn main() {
@@ -203,7 +227,6 @@ pub trait TokenStream {
     /// and `.token()`.
     ///
     /// ```
-    /// # extern crate tantivy;
     /// # use tantivy::tokenizer::*;
     /// #
     /// # fn main() {

src/tokenizer/tokenizer_manager.rs

@@ -1,4 +1,3 @@
-use crate::tokenizer::box_tokenizer;
 use crate::tokenizer::stemmer::Language;
 use crate::tokenizer::BoxedTokenizer;
 use crate::tokenizer::LowerCaser;
@@ -8,7 +7,6 @@ use crate::tokenizer::SimpleTokenizer;
 use crate::tokenizer::Stemmer;
 use crate::tokenizer::Tokenizer;
 use std::collections::HashMap;
-use std::ops::Deref;
 use std::sync::{Arc, RwLock};
 
 /// The tokenizer manager serves as a store for
@@ -25,16 +23,16 @@ use std::sync::{Arc, RwLock};
 ///  search engine.
 #[derive(Clone)]
 pub struct TokenizerManager {
-    tokenizers: Arc<RwLock<HashMap<String, Box<dyn BoxedTokenizer>>>>,
+    tokenizers: Arc<RwLock<HashMap<String, BoxedTokenizer>>>,
 }
 
 impl TokenizerManager {
     /// Registers a new tokenizer associated with a given name.
     pub fn register<A>(&self, tokenizer_name: &str, tokenizer: A)
     where
-        A: 'static + Send + Sync + for<'a> Tokenizer<'a>,
+        A: Into<BoxedTokenizer>,
     {
-        let boxed_tokenizer = box_tokenizer(tokenizer);
+        let boxed_tokenizer = tokenizer.into();
         self.tokenizers
             .write()
             .expect("Acquiring the lock should never fail")
@@ -42,13 +40,12 @@ impl TokenizerManager {
     }
 
     /// Accessing a tokenizer given its name.
-    pub fn get(&self, tokenizer_name: &str) -> Option<Box<dyn BoxedTokenizer>> {
+    pub fn get(&self, tokenizer_name: &str) -> Option<BoxedTokenizer> {
         self.tokenizers
             .read()
             .expect("Acquiring the lock should never fail")
             .get(tokenizer_name)
-            .map(Deref::deref)
-            .map(BoxedTokenizer::boxed_clone)
+            .cloned()
     }
 }